Energy Storage without the cost of a battery

News articles grab attention with stories that electricity utilities may want to turn off rooftop solar PV systems at times, and to turn off air conditioning systems at other times. 

What you won't find are articles on how appliances provide options for individuals and businesses themselves to adjust their energy production and consumption to best support the electricity grid. These options do not require any power for electricity utilities to interfere in how people run their own homes and businesses. 

How a Hot Water System can provide 4 kilowatt hours or more energy storage 

Many hot water systems are designed to operate as follows: 

1. Heat water to a minimum of 60℃. This is to prevent the growth of harmful bacteria. 
2. Ensure water is delivered from the hot water system at no more than 50℃. This is to lower the risk of scald injuries. 
3. Optionally, heat water to a maximum of 70℃ or 75℃. This is to allow more hot water, at 50℃, to be available. 

The delivery temperature of 50℃ is achieved by mixing the stored hot water with some cold water in a Temperature Limiting Device. 

 

The amount of energy needed to heat 90 litres of water from 60℃ to 70℃ is 1 kilowatt hour.

A 360-litre Hot Water System, for instance, can be used to store 4 kilowatt hours of electrical energy by raising the temperature of water in it from 60℃ to 70℃. 

There is no need to buy a battery to store energy if you own a suitable Hot Water System. 

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The Argument for Smart Switches

Time of Use charging has long been proposed to "encourage" electricity consumers to avoid using electricity at times when demand is highest. However, if you examine the National Electricity Market data, you will find that this is not especially helpful. The reason is that there are periods of extremely high wholesale (NEM) prices when demand is relatively low, and conversely, there are times when there are very low wholesale prices when demand is quite high. Moreover, these intervals do not conveniently coincide with any particular time of the day that "Time of Use" charging requires.

It is more appropriate to adjust the system so that electricity is preferably consumed when the wholesale (NEM) price is relatively low, and avoid consuming electricity at those times when the price is extremely high. This can be implemented with "smart chargers" that examine the NEM price before deciding whether to store energy - in a Hot Water System, an Electric Vehicle Battery, or a Home Battery.

Analysis of the National Electricity Market Data for NSW in November and December 2024 (see "How to lower the price of electricity") that shows that the price of electricity consumed in a small proportion of the time contributed enormously to the overall cost of electricity consumed in those months. Smart switches that help to reduce electricity consumed in such periods, and preferably store more electricity whenever the price is relatively low, can lower the total cost.

Diesel Locomotives may be powered by Grid-Scale Batteries

The New South Wales Environment Protection Authority commissioned a study in 2014 on the emissions and efficiency of diesel locomotives in use by Pacific National - "DIESEL LOCOMOTIVE Fuel efficiency & Emissions Testing". 

Pacific National Diesel-Electric Locomotive NR121

 

The test report includes the electric power output of the diesel engines used in the testing program, and the quantity of fuel needed for operating the locomotives between Melbourne and Brisbane. 

This data allows the calculation of the output and storage capacity of a grid scale battery that, if installed in a rail car, would replace the diesel engine, electric generator, and diesel fuel used by Pacific National's diesel locomotives. 

The financial analysis - to choose the time for conversion from diesel to battery power - is a separate matter. When the business case favours the conversion will depend on the falling cost of grid-scale energy storage options and the security of diesel fuel supplies. It is only a matter of time. That is to say it is a question of "when", not "if", the conversion is a good financial proposition. 

The energy requirements. 

Two Pacific National diesel locomotives are described in the report for the NSW EPA. 

Each had diesel electric power output of between 3,000 and 3,500 kilowatts - about 3.5 MW. 

The fuel capacity was 12,500 litres of diesel fuel - sufficient for operating from Melbourne to Brisbane without refuelling. 

The fuel consumption was about 210 grams of diesel for each kWh generated. 

Diesel has a density of about 0.85 kilograms per litre.  See "2.3.5 Diesel Fuel".

With a few calculations - 12,500 litres of diesel weigh 10,625 kgs. 

At 210 grams per kWh, 10,625 kgs of diesel can generate a little over 50,000 kWh or 50 MWh of electrical energy. 

A grid-scale energy storage unit able to deliver 4 MW of output power with 50 MWh of storage capacity is in the range of Battery Energy Storage Systems currently being delivered be energy storage manufacturers. 

See for example -  "In New York, a high-level demonstration project is using a 4 MW / 40 MWh battery storage system..." reported in Battery Storage Paves Way For a Renewable-Powered Future

The Business Case.

Pricing information and other details required for a financial analysis and business case for converting Pacific National's diesel locomotives to battery energy storage systems for the time being is not easily obtained. 

Some indicative estimates can be calculated - 

• 12,500 litres of fuel are loaded for a single trip from Melbourne to Adelaide. At $1 per litre, the fuel costs $12,500. 
• Electrical energy for the trip is 50 MWh. At $50 per MWh, the energy cost would be $2,500 - a saving of $10,000 per trip. If 200 trips were made each year, the fuel saving would be $2 million per year. 

If it is physically not practical to use a 50 MWh Battery Energy Storage System due to its size and weight, this could explain the interest in development of hydrogen with fuel cell technology for rail transport. See "Coradia iLint™ – the world's 1st hydrogen powered train" -

It was at InnoTrans 2016 in Berlin that Alstom presented the Coradia iLint™ for the first time. The launch of the CO2-emission-free regional train that represents a true alternative to diesel power positioned us as the first railway manufacturers in the world to develop a passenger train based on hydrogen technology. And just two years later, at 2018, the iLint™ entered into commercial service in Germany.

Further Reading.

A recent research paper provides a summary of weight and volume characteristics of energy storage systems for potential application in rail transport - "Energy storage devices in electrified railway systems: A review"

 

 

Community Batteries

"A community battery is a relatively new concept in Australia. It is a shared battery solution located in a local neighbourhood and allows customers and the wider community to share in the multiple benefits that batteries can provide." (See Ausgrid "Community Batteries")

Margaret River trials unique community battery

Labor’s Community Battery policy will reduce power bills and emissions for hundreds of thousands of Australians.

Good climate policy is good economic policy. pic.twitter.com/XiMV0OfldV

— Chris Bowen (@Bowenchris) April 1, 2021

Being able to aggregate data at a "community level" will be very helpful.
Consider this data at the level of a single dwelling:
5kW peak demand, 24 kWh / day total.
Now: 5 kW generation and grid capacity needed, mostly unused.
Storage: Only 1 kW of capacity needed.

— Askgerbil Now (@Askgerbil) April 2, 2021

Under ideal conditions, only 1 kW of generating capacity and grid capacity is needed to provide the total of 24 kWh per day used by the above single dwelling. The "community battery" provides the peak demand of 5 kW from time to time during each day as appliances switch on and off.

The battery can be an alternative infrastructure item, potentially replacing 4 kW of generating capacity and grid capacity for the single dweliing in this example.

Even if there is no rooftop solar PV systems in some communities, the ability to charge a community battery overnight - when generation and grid capacity is otherwise idle - can help to lower peak capacity needed the following day.
Policy to raise grid investment to be reviewed?

— Askgerbil Now (@Askgerbil) April 2, 2021

Transition from thermal coal exports

Australia exports 200 million tonnes of thermal coal each year.

Japan is the largest importer, importing 80 million tonnes per year. In planning to eliminate its reliance on fossil fuel imports, Japan is looking to CO2-free hydrogen to replace its imports of coal and LNG, used primarily for electricity generation, and oil, used primarily for road transport.

One step in the 20-year transition timetable is to invest in large solar PV installations in Saudi Arabia and construction of a 'hydrogen pipeline" to deliver hydrogen produced by electrolysis to Japan.

Another step is the construction of combined-cycle gas turbine power stations that have integrated gasification plants to convert imported coal to gas to fuel them. These plants can later run on hydrogen when sufficient supply is available.

Australia and Japan could co-ordinate projects in this transition of Japan's energy systems.
One of the benefits of co-ordination is that Australia's industry and workforce has a planned transition in how it prepares energy for export, adapting employment skills and infrastructure as the plan progresses.

Another of the benefits is that part of the infrastructure development is undertaken by Australia, sharing the effort so that Japan can focus its investments on the most efficient technology to use the energy it imports.

The long-term transition would see Australia's coal export terminals replaced with hydrogen export facilities and the fleet of bulk ore carriers replaced with specialised hydrogen shipping vessels. The coal mining workforce would gradually be replaced with a workforce that constructs and operates hydrogen production plants.

During the early years of the transition it may be beneficial to convert hydrogen and coal to methane and make use of existing natural gas pipelines, LNG export terminals and LNG tankers to transport the hydrogen to Japan's existing LNG import facilities.

One benefit for Japan would be to avoid the time and cost of building integrated coal-gasifiers with new combined-cycle gas turbine power stations and fuel cell generators. The gasification can be carried out in Australia before exporting the coal with hydrogen as LNG.

Large-scale solar farms are currently built with inverters that are a significant part of the cost.
The inverters change direct-current electricity produced by the solar panels into alternating-current electricity for distribution on the electricity grid.

Inverters aren't needed when the goal is to produce hydrogen by electrolysis with the electricity generated.

A second income-stream from renewable electricity production will assist farmers struggling with drought near coal-mining regions. Solar PV installations could be designed to be "stock-friendly" for Australian livestock producers, and not copies of European installations where fields are covered with closely-spaced solar panels just above ground level.

Cattle and solar PV systems

The renewable energy generated would be fed to electrolysis units creating hydrogen.
The hydrogen is to be transferred into methanation units that have pulverised coal handling equipment where the hydrogen and coal is transformed into methane, ready for transfer to LNG export terminals.

Thyssenkrupp coal handling system

Gasification technologies

See Thyssenkrupp Australia - "Power-to-gas: Storing wind and sun [energy] in natural gas"

The 2015 Japanese government report "Overview of Assessment by Power Generation Cost Verification Working Group", Institute of Energy Economics, Japan (IEEJ) explained that renewable energy costs are higher in Japan than in other countries, and showed Australia has a comparative advantage in large-scale wind and solar installations.

"Unit construction costs for solar PV and wind power generation systems in Japan are higher than in other countries. ...Apparent factors behind the cost gap include higher personnel costs, complex topography and FIT scheme introduction backgrounds in Japan." (at pages 8-9)

"Saudi Arabia and Japan's SoftBank expanded their partnership on Tuesday, announcing the world's biggest solar power generation project at a press conference in New York."
The 200 gigawatt solar power project was estimated to cost $200 billion. https://t.co/MOsH9HvsMG

— Askgerbil Now (@Askgerbil) August 10, 2018

"This new material provides superior hydrogen production with lower energy requirements. This enables hydrogen production from renewable energy sources such as solar and wind generated power." @UNSW https://t.co/rZBIg7PDjz #ausbiz #jobs #ausunions @CFMEU_ME

— Askgerbil Now (@Askgerbil) August 7, 2018

Related posts:

Australian energy exports

Keeping waste plastic out of landfill

 

Consumerism in an ecosystem

Rain forests are centres of great activity that depend on quite small reserves of nutrients.

Plants continuously absorbing sunlight transform water and carbon dioxide into polymers, mainly cellulose, and release oxygen.

On the rain forest floor, a myriad of animals and insect munch their way through fallen leaves and branches, breaking the polymers into water and carbon dioxide. Their waste releases the very small nutrient reserves back into the thin soil layer where they are once again available to the plant community.

Caterpillar eating a leaf

A productive rain forest ecosystem harboring a great variety of living organisms is a stark contrast to a desert landscape in which far fewer living things eek out a sparse existence.

Human activity might be viewed as damaging and harmful to the environment, and though this is sometime a reasonable observation, it does not have to be.

Consumers supporting producers and discarding obsolete items provide a level of economic activity to engage people and allow their participation in economic and social life.

That discarded items accumulate and are not reprocessed is a problem that can be solved.

Steel and aluminium can be reprocessed more or less indefinitely. Demand for new steel and aluminium eventually declines in economies as the accumulated volume being recycled meets more and more of demand.

Collecting municipal waste, then sorting, recycling and reprocessing at large central plants has been a fairly universal approach for some time. New technology may allow for some waste material to be reprocessed at or near the point of origin, reducing the cost and complexity of large-scale collection and sorting.

Many waste items that are compounds of only carbon, hydrogen and oxygen can be completely decomposed into a gaseous fuel and may be substituted for natural gas in space heaters and hot water systems.

There is no need for waste materials to accumulate and degrade the environment. Creative solutions can be found. Many creative solution exist but simply aren't well known, hence the word "found" rather than "developed".

Energy in the Future

One creative solution that does not exist but may be developed is a business model and technology for virtually unlimited energy at little or no cost.

One possibility is a process to transform materials from one nuclear structure to another that is commercially viable and that generates energy as a byproduct. The energy byproduct can be distributed for a nominal charge.Transforming nuclear waste into safe, naturally occurring and valuable isotopes is a possible additional benefit.

Australian energy exports

Japan intends to establish a "hydrogen pipeline" to replace its existing imports of energy from Australia and elsewhere.

To speed up the development of a "hydrogen pipeline" for Japan, Australia may be able to adapt existing energy infrastructure for the purpose.

Hydrogen produced by renewable energy creates a number of challenges for special-purpose overland transport and shipping. An interim processing strategy can skip over these challenges and re-use existing infrastructure, saving time and money. A little chemistry explains how this can work...

When hydrogen is combined with carbon dioxide to form methane and water, the energy content in the methane is about the same as the energy that was present in just the hydrogen:

CO2 + 4H2 → CH4 + 2H2O

In the above reaction half of the hydrogen combines with oxygen from the carbon dioxide to form water. The other half of the hydrogen combines with the carbon from the carbon dioxide to form methane. This is known as the "Sabatier reaction". It is used commercially by Audi to create "e-gas" for its Compressed Natural Gas vehicles.

Natural gas is essentially methane with smaller amounts of other gases such as carbon monoxide and ethane. Methane made from hydrogen can be transported through natural gas pipelines and shipped as LNG - liquefied natural gas - from Australia to Japan using existing LNG terminals and LNG tankers.

When methane is combined with water to form hydrogen and carbon dioxide, the energy content in the hydrogen is about the same as the energy that was present in just the methane:

CH4 + 2H2O → 4H2 + CO2

In the above reaction oxygen from the water combines with carbon from the methane to form carbon dioxide. All the hydrogen that was part of both the methane and water is separated. This is known as "Steam Methane Reforming". It is widely used in industry to manufacture hydrogen from natural gas.

The carbon dioxide produced in the above reaction may be liquefied in Japan and returned to Australia on the empty LNG ships that delivered the methane.

This allows the carbon dioxide to be re-used indefinitely in Australia to convert hydrogen to methane for shipping to Japan using existing natural gas pipelines, LNG terminals and tankers.

Electric vehicles make solar power mobile

Solar PV systems can reduce electricity bills for many families and businesses.

Unfortunately this isn't the case for families who rent because properties available for rent rarely have solar panels installed.

Even for families who do have solar PV systems, the savings aren't that great when everyone is at work or school during the the day when the sun is shining and the solar energy output is mostly being fed into the grid.

There is another way to supply solar energy to these households and help them cut their electricity bills.

Many businesses are saving on their power bills by installing solar panels, but the savings would be greater if they had batteries to provide power early in the day and late in the afternoon when the output of the solar system is below the midday peak output.

Suppose a business with a solar PV sysytem buys 4 or 5 electric vehicles that can deliver electricity from their batteries - the Nissan Leaf with a 40 kilowatt-hour battery is one electric vehicle designed for this role -  and leases them to its workers to be used in the following way:

• The worker drives the electric vehicle to work each morning and plugs it into a power exchange socket where it provides electricity to the business whenever electricity use is greater than the output of the solar PV system AND has its battery recharged whenever there is excess solar energy being produced. 
• The worker drives the car home each day after work and plugs it into a power exchange socket where it powers the home - with solar energy stored during the day while at work - during the evening peak period when electricity prices are at their greatest. 
• By late evening or early morning, if the car battery charge has fallen below the level that is needed for the morning peak period to prepare breakfast and for the commute to work, some additional energy from the grid is stored in the battery - again at off-peak rates.
• ...and so on, each day.

This may make electric vehicles a better investment than just assessing their value as a replacement for a simple petrol-fueled vehicle. They can provide electricity as backup generators for businesses when solar energy output is less than the amount of electricity used and they can let workers take solar energy home. This is especially valuable for anyone who lives in rented accommodation and/or lives in one of the many households where all the members are away from the home during daytime.

The following video uploaded in 2013 describes the process in 2 minutes. At that time, the Nissan Leaf had only a 24 kilowatt-hour battery. The recently released model has a 40 kilowatt-hour battery. 

One application of the technology is described in Adam Vaughan's the article published in The Guardian on October 3, 2017:

Electric car owners 'can drive for free by letting energy firms use battery' 

Electric car owners will be paid for letting an energy company use their vehicle’s battery in a pioneering scheme to increase take-up of the cleaner vehicles and help power grids manage the growth in green energy.

Nissan and one of the UK’s biggest challenger energy suppliers, Ovo, will offer the “vehicle-to-grid” service to buyers of the Japanese carmaker’s new Leaf from next year.

After installing a special charger in a customer’s home, the supplier will take over the management of the car’s battery, with owners able to set a minimum amount of charge they want for driving the next day. Ovo will then automatically trade electricity from the battery, topping it up during off-peak periods when power costs about 4p per kilowatt hour (kWh), and selling it at peak times for about four times as much.

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Value for investment dollars - Snowy Hydro vs Plasma Gasifiers

The Snowy Hydro 2.0 project is one possible way to store renewable energy.
For each 100 megawatt-hours of electricity stored about 70 megawatt-hours is likely to be generated and delivered to consumers - after allowing for pumping, generation and distribution losses.

If the wholesale price of electricity is $70 per megawatt-hour, each 100 megawatt-hours to storage will cost $7,000. The amount available for delivery - 70 megawatt-hours - will thus cost $100 per megawatt-hour. (That is $7,000 for the 100 megawatt-hours of electricity stored divided by the 70 megawatt-hours delivered to consumers.)

The result is a 40 percent increase in the wholesale price of electricity.
If the purpose is to lower the price of electricity, Snowy Hydro 2.0 project isn't looking too good on this part of the assessment.

The next step is to consider the cost of constructing the scheme, and the need to pay interest to the investors on the amount. This is another problem for the goal of reducing the price of electricity. It is aggravated by the fact that the project lead time means that interest costs accumulate for many years before there is any opportunity to begin recovering those costs from electricity consumers.

Another possible of way of storing renewable energy is to run plasma gasification units with electricity to be stored, converting waste that would otherwise go to landfill into synthesis gas.

Westinghouse Plasma Gasification
Converting Waste Into Clean Energy for a Healthier Planet

These plants are able to deliver over double the amount of energy that is used to operate them.
For each 100 megawatt-hours of electricity costing $7,000 stored in synthesis gas, at least 200 megawatt-hours is available for delivery to consumers - reducing the wholesale price of electricity to $35 per megawatt-hour - a reduction of 50 percent in this stage of the analysis.

Unlike Snowy Hydro 2.0, the assessment of value for investment dollars gets better, not worse, in the next phase. The elimination of waste heading to landfill represents a further cost-saving for investors.

That plasma gasification units can be built quickly means the return on investment begins far sooner than is possible for Snowy Hydro 2.0.

Related post - Efficient renewable energy storage, waste recycling and zero fossil fuels

Gas Vision 2050 by 2025

Gas Vision 2050 is an Energy Networks Australia report produced on December 18, 2017. Australia’s peak gas industry bodies prepared it to "demonstrate how gas may continue to provide Australians with reliable and affordable energy in a low carbon energy future."

The scope of the report is to "outline how Australia’s gas supply and infrastructure can be a national advantage as our energy mix continues to evolve."

Summary report: Decarbonising Australia’s gas networks https://t.co/ExfzLTjH4T #ausenergy #gas pic.twitter.com/fSLT6VmcHj

— Energy Networks (@EnergyNetworkAu) December 18, 2017

The reports author's missed the option being explored across Europe: make us of Australia’s gas supply and infrastructure as an energy storage system.

This new purpose for Australia’s gas supply and infrastructure has the potential to make a substantial contribution to the economy. For instance, a proposal for a multi-billion dollar development of pumped hydro energy storage "Snowy Hydro 2.0" is years away from becoming a reality. The gas supply infrastructure can begin providing this function almost immediately.

The report describes three technologies under the heading "Decarbonisation Pathways" -

• Biogas production – Biogas consists of methane and is already produced from municipal solid waste.
• Hydrogen: Hydrogen can be produced from natural gas or through electrolysis. Hydrogen creates opportunities for clean energy for households, businesses or transport and can also generate zero emissions electricity using fuel cells or gas turbines.
• Carbon capture and storage (CCS) refers to the process of producing decarbonised hydrogen from gas, coal, or biogas to remove carbon dioxide from the carbon cycle.

There is a fourth technology that has significant potential to accelerate decarbonisation of Australia's gas supply. So much so that the goal the report sets for 2050 may be achieved much sooner.

Biogas can be produced from a great many carbon-containing materials such as farm crop waste, municipal waste, sewage sludge, animal waste and timber waste. In each case about half the carbon combines with hydrogen from water in the mixture to form methane and the remaining carbon combines with the oxygen "left over" from the creation of methane to form carbon dioxide.

The result is a gas that is about 50/50 methane and carbon dioxide. The carbon dioxide needs to be removed before the methane is suitable for injection into gas supply pipelines.

Hydrogen can be produced using surplus renewable energy to split water by electrolysis. This is a method of energy storage. Hydrogen may be injected directly into gas supply lines, but the proportion can be no more than 10 percent by volume.

The fourth technology that isn't mentioned in the Gas Vision 2050 report tackles both of the above issues:

Waste materials containing carbon can be reacted with hydrogen. In this process ALL the carbon is converted into methane and NO carbon dioxide is created. So there is nothing to separate from the biogas before it can be injected into natural gas pipelines. The 10 percent limit on the proportion of hydrogen that can be safely mixed with natural gas is no longer an issue...

The biomethane produced via this pathway is achieving two purposes:

• It is replacing natural gas with carbon-neutral biogas. 
• It is storing renewable energy in the form of methane for use as required.

This needn't be a permanent part of a zero-emission energy system. While battery capacity investment is ramping up, excess wind and solar power can be stored and distributed as hydrogen and/or methane in the existing natural gas system.

Burning natural gas in heating appliances will eventually be discontinued, but for now, a large number of these appliances are being used. It will be some time before they are all replaced.

Small distributed gas-fueled electricity generation can be up to 60% efficient. These do the job that batteries and pumped hydro will eventually do - when enough of them have been built.

Farmers can replace coal seam gas industry by manufacturing methane from crop waste that is combined with hydrogen made to store  renewable energy.

When there are enough batteries and pumped hydro storage to eliminate the need for natural gas energy resources in Australia, this bio-methane can be used as feed stock in chemical industries to replace coal seam gas. It can also be exported as LNG, substituting for Australia's coal and coal seam gas energy exports.

Affordable reliable electricity the easy way

Australian Government politicians often begin media announcements about energy with the phrase "What do you do when the sun doesn't shine and the wind doesn't blow?"

I suppose they often ask this because they don't know the answer. If they did, surely they'd have stopped asking themselves the same question ages ago.

Another over-used phrase the Australian Prime Minister repeats to himself  is: "When you flick the switch, you want the light to come on."

Many old people still think the electricity grid runs like it did in the 1950's: demand for electricity sprang up from the random actions of countless people flicking light switches on and off willy-nilly and the electricity generation and distribution system, startled by all this activity, sprang into life to send the right number electrons down wires to make their lights come on.

Today, managing electricity supply and demand is much easier. It is also a lot cheaper: it was expensive to keep enough capacity spinning at all hours of the day just in case another 300 or 400 people suddenly flicked on light switches at the same time.

Weather forecasts make it easy to predict a day ahead how much energy any customer is going to need and how much energy the customer's solar panels are going to generate.

Data on customers' energy use and production at five minute intervals is available with historical data for several years with which to predict changes from season to season and forecast energy demand on exceptionally hot or exceptionally cold days. It is available for analysis at PVOutput which is a free service for sharing and comparing PV output data.

The following chart is an example of data for one day of a household with a 5 kilowatt solar PV system and all electric appliances:

The chart shows output from a 5 kilowatt solar PV system - that begins generating electricity about 7:00 am in the morning and ceases generation about 5:30 pm - producing a total of 20 kilowatt-hours of energy for the day.

Also shown is the energy consumption by appliances in the household. Though this seems to proceed at a fairly steady pace through the day, details in the source data show that there are a number of short bursts of energy use and relatively quiet periods.

The grey line shows the difference between energy generated and energy used. The total produced for the 24 hour period on this day was slightly above the total used.

The solar panels however didn't produce energy early enough in the day to match the energy used before 9:00 am, and stopped producing electricity when the total amount used was only about 12.5 kilowatt-hours at 5:30 pm.

If the household had a 15 kilowatt-hour battery for energy storage:

• Beginning the day with 5 kilowatt-hours stored energy would have supplied the morning energy needs in the hours before the solar panels began to produce enough energy to meet the demand.
• Adding about 12.5 kilowatt-hours of solar energy to the battery by 5:30 pm would be sufficient to continue meeting demand for the rest of the day.
• As the total energy generated for the day was slightly greater than the total consumed, the battery would end the day at about the same level of charge it had at the start of the day - ready to repeat the process the next day.

 If the energy used was a little greater than initially predicted, or the amount generated was a little below the amount forecast a day earlier, the battery would end the day with a bit less than the 5 kilowatt-hours of energy stored that it held at the beginning of the day.

The battery management software could then place an order for a 'top-up' to be sent to it after midnight - while spare generating capacity and distribution assets are sitting idle doing very little. The automated battery 'top-up' order could be modified by energy management software to take into account the weather forecast for the following day.

Energy is very cheap to generate and deliver after midnight: beat the rush, save money.

So the next time someone asks "What do you do when the sun doesn't shine and the wind doesn't blow?" tell them.

Future energy technology is here

Australia ran an expensive experiment to encourage investment in electricity generation and distribution capacity to ensure supply on a few days of the year when demand is at a maximum.

Electricity demand on the hottest days in summer is about double the average electricity demand on other days. To encourage investment in capacity that is idle on all but these few extremely hot days each summer, a very profitable incentive was created.

State-owned electricity generators and distribution network operators that were able to borrow $billions at discounted interest rates were guaranteed a high rate of return on every dollar they could spend. The inevitable result was excessive and extravagent spending. It is commonly known now as "gold-plating".

As an aside, it is sometimes misunderstood that switching from coal-fired power generation to low-emission electricity generation increases prices. Note that the US maintained low electricity prices while making rapid progress on replacing coal-fired power stations.

Technology is available to solve the problem that Australia created with these incentives to spend up big on electricity generating and distribution capacity that is planned to be idle on all but a few of the hottest days each summer.

This technology also solves the problem of what to do with the surplus electricity supply when the sun is shining on solar panels and the wind is spinning wind turbines, but all available battery storage is filled and demand is being fully met...

Distributed power-to-gas plants can convert the surplus electricity into renewable natural gas. This can be fed into the existing natural gas distribution lines to flow upwards to liquified natural gas plants for export. On the few occasions each year when electricity demand is exceptionally high, as many distributed power-to-gas plants as required can be reversed within a few minutes to generate electricity from natural gas stored in the natural gas distribution lines.

Renewable natural gas produced from farm and urban waste can be fed into the natural gas distribution lines and, where carbon dioxide has been separated from biogas, it can be piped to power-to-gas plants that combine carbon dioxide with hydrogen to produce renewable natural gas.

Australia is in the fortuitous position of being able to use renewable energy for 100 percent of its electricity supply, 100 percent of its transport energy and 100 percent of its energy exports.

Sunfire GmbH Earns Top Prize In the 2016 Innovation Climate Protection Awards for "Reversible Elec | FuelCellsWorks https://t.co/pYfHWKVicf

— Askgerbil Now (@Askgerbil) September 4, 2017

Sunfire GmbH Earns Top Prize In the 2016 Innovation Climate Protection Awards for "Reversible Elec | FuelCellsWorks (from @waybackmachine archive of article) https://t.co/9al5XfWCX1

— Askgerbil Now (@Askgerbil) June 25, 2020

The fabulous Professor Amal @UNSW @UNSWEngineering @WomenSciAUST Australian power for the future https://t.co/0b3nCHW2aY

— Laura Poole-Warren (@la_warren) August 20, 2017

Renewable energy 24/7: waste water + sunshine + CO2 converted to renewable #natgas with help from algae and bacteria https://t.co/S7ZUuzorWx

— Askgerbil Now (@Askgerbil) September 5, 2017

The Odd Type of Water That Can Start Fires - at just 373°C | NASA Space Science HD https://t.co/pkLPS5pCjd

— Askgerbil Now (@Askgerbil) September 5, 2017

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Renewable energy technology is affordable and reliable

Incumbent electricity and transport fuel producers lobby to hold back the adoption of renewable energy, but innovation has now eliminated the logic of their concerns.

When the roll-out of Australia's first-generation electricity supply system was finalised in the 1960's it relied upon simple management strategies for economic use of the capital investment:

• Coal-fired power stations met electricity demand during peak loads during the day and at night heated off-peak hot water systems and stored further energy in pumped hydro storage.
• The pumped-hydro storage system was available to supplement the coal-fired power generation capacity during the highest peak demand periods during each day. 

With the low cost of small-scale energy storage that is now available, it is practical to transfer the 1960's experience with centralised  electricity generation into managing electricity supply for individual homes, businesses and villages...

A large household in Australia uses up to 20 kilowatt-hours of electricity a day - about the same amount of energy that a 5 kilowatt rooftop solar photovoltaic (PV) can produce reliably on most days of the year.

For reliable electricity supply, a household only needs to install enough battery storage to provide it with all the energy it needs for just one day. On most days, the solar PV system will recharge all the energy used from the battery storage, and the household can meet occasional peak loads by drawing energy from both its solar PV system and battery storage at the same time.

Solar Battery Storage Comparison Table
Extract from SolarQuotes table

On days where solar PV energy output is below the usual level, the battery storage system can be topped-up overnight from large-scale generators. The large-scale generators can be informed of the total overnight demand well in advance - from data transmitted from battery storage systems, and schedule generation and distribution at times to make use of unused distribution capacity. This is like having supermarkets restocked by trucks using roads at 3 am in the morning to deliberately avoid busy peak-hour traffic.

In periods of extreme day-time peak demands, the large-scale generators can be brought online to supplement the regular levels of demand that are met by solar PV and battery storage of homes, businesses and villages.

This strategy eliminates the need for 'gold-plating' which is the major cause of high electricity prices in Australia: idle capacity for generation and distribution that is kept in reserve for as little as a few hundred hours each year when peak demand reaches unusual, extreme levels.

Energy storage and meeting peak demand

The cost of storing energy and meeting peak demand can be cut dramatically with a good combination of technologies and judicious use of available assets.

Depleted gas fields in South Australia have provided a return on investment over a number of years and when reused for new purposes, save the need for investment in locating and tapping similar geological structures.

Subsurface geological conditions which may be suitable for underground gas storage have been identified in the Two Wells - Port Wakefield area of the Northern Adelaide Plains. This area is within 100km of Adelaide. (See "Underground Gas Storage", Department of the Premier and Cabinet, South Australia)

A cutaway view of Solar Turbines' Taurus 70 engine, which is similar to a jet engine, but is used to generate electricity in power plants on the ground.

In a solar thermal turbine compressed air is heated by concentrated solar energy...

CSIRO Solar Air Turbine Project

Heat energy in a solar thermal turbine can be supplemented with natural gas when there is partial cloud cover. At night natural gas can take over from solar thermal heating.

Whether a turbine engine is run on natural gas or solar thermal energy, about half the energy available from the turbine is used to power the compressor, leaving the other half to run a generator to supply electricity.

That is, a gas turbine power station with a nameplate rating of 100 MW is actually able to produce 200 MW of energy - if it did not have to drive a compressor.

Energy from renewable energy generators may be stored by driving compressors to compress air that is stored in depleted gas fields.

Compressed Air Energy Storage

The compressed air energy storage can deliver electricity to the grid when it is required by supplying it to a gas turbine generator, relieving the generator of the need to drive a compressor while it is being supplied with compressed air.

A solar thermal power station can store energy in a compressed-air energy store and use the compressed air at night to significantly reduce the amount of stored thermal energy or natural gas needed for operation.

During peak demand periods, output from existing gas turbine generation plant can be quickly increased by reducing the energy used to drive compressors while supplying them with compressed air from storage.

Practical Energy

The requirement statement for practical energy -

What can be done collectively to ensure reliable, affordable and clean energy? https://t.co/5JmelgXzIF

— IEA (@IEA) April 12, 2017

The answer is surprisingly simple.

There are 4 or 5 processes that do more-or-less the same thing in slightly different ways. Each was designed with a different purpose in mind, but that doesn't mean they can't be used for other purposes the designers hadn't considered.

Bioenergy, waste-to-energy, renewable energy storage as synthetic natural gas, biogas and synthetic natural gas from coal are different ways of doing the same thing.

Synthetic natural gas can be used to store energy, to generate electricity on demand, and as feedstock in manufacturing processes. Synthetic natural gas can also be manufactured for export in the form of LNG.

It can be made from 100 percent renewable energy, 100 percent fossil fuel energy, or some combination of both renewable and fossil energy. This allows a transition to a 100 percent renewable energy future, achieving the  above requirement statement: ensuring reliable, affordable and clean energy.

The underlying process combines carbon dioxide, water and energy to create methane and oxygen:

CO₂ + 2H₂O → CH₄ + 2O₂

• Photosynthesis by plants and algae to create biomass that methanogenic bacteria convert to methane is one way of doing this with solar energy.
• Waste-to-energy can use methanogenic bacteria to produce methane using the solar energy embedded in the waste.  
• Electrolysis of water to produce hydrogen that is reacted with carbon dioxide to make methane is another way of doing this with solar PV systems and wind turbines.
• Biomass can be converted to methane in high temperature superheated water reactors. The thermal energy to do this can be from concentrated solar thermal energy, or from reaction with either oxygen or hydrogen created by electrolysis of water.
• Biomass can be converted to methane in very high temperature gasifiers that create carbon monoxide and hydrogen that is reacted in a separate step to create methane. The energy for this high temperature process can be obtained by burning a portion of the feedstock in air. 

In each of the above processes that use biomass to produce methane, coal can be used in place of some or all of biomass.

When there is sufficient solar PV and wind turbine generating capacity, hydrogen can be produced whenever electricity supply exceeds demand. This hydrogen can be reacted with carbon dioxide to make methane for generating electricity whenever demand exceeds the supply.

With sufficient renewable energy generating capacity, synthetic natural gas can be manufactured for export - providing completely renewable energy to importing countries via existing LNG export, transport and import infrastructure.

Curiously, coal is presently being converted to synthetic natural gas in the most environmentally 'unfriendly' option available - burning a portion of the coal in air to create carbon monoxide and hydrogen that is reacted in a separate step to create methane. This technology has been criticised for its high level of carbon dioxide emissions and water usage.

Coal could be converted to methane by reacting it with hydrogen produced by electrolysis of water with electricity from solar PV systems and wind turbines. It can also be converted to methane in high temperature superheated water reactors. The thermal energy to do this can be from concentrated solar thermal energy, or from reaction with hydrogen created by the electrolysis of water.

This is most suitable for low-grade lignite such as that found in Yallourn Valley in Australia that consists of 50 percent or more water. With this process it can be converted to high-value synthetic natural gas, avoiding the need for coal seam gas.

Its use can be gradually phased-out as renewable energy generating capacity increases to the stage where it can completely replace it.

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Renewable natural gas can turns organic waste into usable fuel. An ideal use? Large trucks. #sustainability https://t.co/blouS4fZZ5 pic.twitter.com/jMSne5nRk8

— UPS Public Affairs (@UPSPolicy) April 17, 2017

Production of synthetic natural gas (SNG) by hydrothermal gasification of wet biomass https://t.co/qJyOyZw9rr

— Askgerbil Now (@Askgerbil) February 26, 2017

Making renewable natural gas from wet biomass, no #CSG -
1/ https://t.co/cbAnvLLgQi
2/ https://t.co/bA1a1XcUY1
3/ https://t.co/Xyy79DHFEo

— Askgerbil Now (@Askgerbil) April 3, 2017

Taking the blinkers off energy policy in Australia

The "Resources and Energy Quarterly" by the Office of the Chief Economist for March 2017 has the following Table of Contents:

Contents

Foreword	4
About this edition	5
Resource and energy overview	6
Steel	25
Iron ore	33
Metallurgical coal	42
Thermal coal	51
Gas	61
Oil	73
Uranium	82
Gold	89
Aluminium, alumina and bauxite	97
Copper	113
Nickel	121
Zinc	127
Trade summary charts	133
Appendix	142

Renewable energy doesn't get a mention.

This oversight is the foundation on which opportunities for Australia's economic development are missed.

Two of the energy resources that are included - thermal coal and natural gas - are shown to have outlooks that aren't very promising in the case of coal and are at risk from high domestic production costs and low-cost competition in the case of gas.

Thermal coal exports for example are shown to decline in value by $5 billion per year to about $15 billion per year, though volumes are supposed to remain the same. Not all Australian coal mines will be commercially viable with this outlook that is actually describing export prices falling by 25 percent.

Natural gas exports as LNG are shown to have a large increase in capacity coming onstream at the same time as an even greater increase in U.S. LNG export capacity - with the U.S. exporters able to source feed gas at much lower prices than Australian exporters.

The quarterly report makes a courageous projection of rising volumes and value of Australian LNG exports even though noting some daunting obstacles:

• Australia is not immune from supply-side competition. The United States will make the largest contribution to new capacity. The cost competitiveness of US exporters will largely be determined by the cost of their domestic gas, for which the reference price is Henry Hub. Henry Hub prices averaged US$3.0 per million British thermal units over the first quarter of 2017 (A$3.80 a gigajoule). 
• While Australia's LNG exports are projected to rise, the capacity utilisation of Australian LNG export projects is expected to decline. The price competitiveness of Australian producers is one factor affecting the outlook for exports. Proximity to Asia will be an advantage, although the Panama Canal expansion in 2016 has lowered shipping costs from the US.
•  A large cost for Australia's LNG plants is feed gas. The three LNG export terminals on the east coast — which are largely fed by CSG from Queensland’s Surat and Bowen basins — tend to have relatively high costs for feed gas. Unlike LNG ventures using gas from conventional reservoirs, LNG operators on the east coast will need to drill hundreds of new wells each year to maintain CSG production, with costs of over a million dollars per well.

Australia has an advantage with ample renewable energy resources to overcome the poor outlook for coal and the high-risk outlook for natural gas.

With the price of coal projected to decline to about $2 per gigajoule, and the cost of coal-seam gas likely to exceed the export price of LNG from US exporters, it is increasingly attractive, if not imperative, to export natural gas made from cheap coal and renewable energy.

Several processes are available to achieve this.

The bottom line is that these processes change 1 gigajoule of coal valued at perhaps $2 into 4 gigajoules of natural gas worth $32 by adding 3 gigajoules of renewable energy.

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Available systems to make synthetic natural gas from cheap wet lignite and brown coal

Production of synthetic natural gas (SNG) by hydrothermal gasification of wet biomass https://t.co/qJyOyZw9rr

— Askgerbil Now (@Askgerbil) February 26, 2017

Making renewable natural gas from wet biomass, no #CSG -
1/ https://t.co/cbAnvLLgQi
2/ https://t.co/bA1a1XcUY1
3/ https://t.co/Xyy79DHFEo

— Askgerbil Now (@Askgerbil) April 3, 2017

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Trump Approves Natural Gas Export Terminal In Bid For Energy Dominance https://t.co/dwp9Csq1PX#tcot #MakeAmericaGreatAgain #AGW #natgas

— Andrew Follett (@AndrewCFollett) April 25, 2017

Energy Secretary says project will create 45K jobs, US world's dominant LNG exporter. Natural gas. https://t.co/1Tse5lGyo7 #auspol #springst

— Askgerbil Now (@Askgerbil) April 26, 2017

Even more ways for energy storage

When people think 'energy storage' batteries often are the first option that comes to mind.

A battery that has been discharged down to 25 percent of its capacity may hold, say, 3.6 gigajoules of electrical energy. 'Recharging' the battery, adding more energy, could increase the energy stored to, say, 14.4 gigajoules of electrical energy. This is the same as 4 megawatt-hours of electricity.

Another option for energy storage doesn't need a battery.

Think of brown coal as a 'battery' that has been almost completely discharged.

The amount of brown coal that can deliver 3.6 gigajoules of electrical energy - if it is burned in a coal-fired power station - contains about 380 kilograms of carbon.

Instead of burning the brown coal, energy can be added, in a similar way a battery can be 'recharged', so that it can deliver 15.5 gigajoules of electrical energy when needed - if it is burned in a combined-cycle gas turbine power station.

There's no need to understand the chemical reactions in a battery when it is being charged and discharged. There are many types of batteries and the chemicals and chemical reactions in each type are quite different.

When renewable energy is stored by adding it to brown coal, chemical reactions also take place, and achieves the same result as recharging a battery - but without the need for the battery.

Simplified process flow diagram of the supercritical gasification system developed by Gensos.

---

Available systems to make synthetic natural gas from cheap wet lignite and brown coal

Production of synthetic natural gas (SNG) by hydrothermal gasification of wet biomass https://t.co/qJyOyZw9rr

— Askgerbil Now (@Askgerbil) February 26, 2017

Making renewable natural gas from wet biomass, no #CSG -
1/ https://t.co/cbAnvLLgQi
2/ https://t.co/bA1a1XcUY1
3/ https://t.co/Xyy79DHFEo

— Askgerbil Now (@Askgerbil) April 3, 2017

Energy security

Energy security and a reasonable cost for energy can be achieved with a number of design options.

One option for a group of homes with solar PV systems is:

• Share an energy storage system that begins each day holding enough energy to make up for any solar PV electricity shortfall.
• During the day use solar PV electricity for each household, only drawing from the energy storage system when demand exceeds the solar PV output.
• At night use a grid-based electricity generator for each household. "Top up" the energy storage system at night where it has supplied power during the day. 
• A number of projects and initiatives are exploring grid-based electricity generator business models. The University of Technology Sydney for instance:
  • "Building a level playing field for local electricity generation"
  • "Facilitating Local Network Charges and Local Electricity Trading"

Having a store of energy to use when you need it provides #energysecurity. Large scale #energystorage using a #vanadium flow battery. pic.twitter.com/DnKijJCLyd

— VSUN Energy (@vsunptyltd) December 22, 2016

The energy storage system provides energy security by supplying electricity whenever solar PV output is reduced by cloud cover.

It also supplies extra capacity for exceptional demand periods with both the energy storage system and the solar PV systems delivering electricity.

CoverTel Power is proud to announce
the first Imergy Vanadium Flow Power system has landed in Melbourne Australia

This is an alternative to gold-plating the electricity grid ("poles-and-wires") to provide extra capacity that is hardly ever needed. It is also an alternative to building power stations that sit idle for all but rare occasions when they are used to satisfy exceptional demand.

The electricity grid and grid-based electricity generators are used more efficiently because they service a consistent overnight demand. There is no need for costly "gold-plating" and expensive reserve capacity. Because of this electricity prices are reduced.

Electric vehicles can also be most conveniently recharged at night. This too improves energy security by eliminating dependence on imported transport fuels.

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Some innovations need system integrators and coordination

Much innovation occurs by incremental improvements in technology. Jet engines gradually replaced piston engines in the aircraft industry. Cathode ray tube television sets have been replaced by flat screen televisions.

Other innovations are not so easily made by incremental adoption. A vehicle manufacture developing the first model able to be fueled by unleaded petrol would have difficulty finding a customer if no petrol station sold unleaded petrol. A petrol station proprietor would be unlikely to stock unleaded petrol when no customers drove vehicles needing unleaded petrol and no oil refinery made unleaded petrol....

Innovations are often disruptive and the benefits come with adverse effects ...

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Fed Govt warns electric cars will hit its bottom line by driving fall in fuel excise revenue https://t.co/KwMJzSGDGO pic.twitter.com/vPyXC1N3Ti

— ABC Current Affairs (@amworldtodaypm) August 16, 2016

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Many innovations only work when they are part of a collection of co-ordinated changes that are adopted across a number of industry participants.

The components needed to make some innovations work may exist in other fields. Industry participants and product developers can benefit from the skills of  system integrators to locate components for a viable design made up from a collection of products that will work well together.

An example of a wandering albatross GPS track

The technology capabilities of The Royal Society for the Protection of Birds, "Tracking seabirds to inform conservation of the marine environment" suggests a way to overcome the quite real concern of the Federal Government that electric cars will hit its bottom line by driving a fall in fuel excise revenue.

Advances in the miniaturisation and mass-production of low-cost, lightweight, high-precision GPS tags, enables tracking the detailed movements of large numbers of seabirds, including some of the smaller species.

"The Turnbull Government is preparing to drive a new debate over how roads are funded in Australia, with the revenue collected from fuel excise expected to shrink in coming years. Right now motorists pay almost 40 cents a litre in tax, delivering close to a $11 billion dollars a year to the Treasury." (@ABCNews, 16 August 2016)

The existing fuel excise that funds roads is raised in proportion to the amount of fuel motorists buy. Motorists who drive only during off-peak times on regional roads pay at the same rate as motorists driving on expressways in cities during peak periods. A replacement technology that can measure the time, distance and location of trips may be sold on the basis that it is more equitable than the existing fuel levy that contributes to road funding.

Mass production of batteries for electric vehicles will drive a significant reduction in their manufacturing cost.

There is an opportunity to combine this predictable reduction in the cost of lithium-ion battery energy storage with the continuing decline in the price of solar photovoltaic (solar PV) systems.

The two technologies don't immediately work well together when people typically drive to work early in the morning and return home late in the day. Any solar energy generated at their home during the day cannot be conveniently used to recharge their electric vehicle.

An option to improve the overall performance and cost-effectiveness of these technologies has been developed ....

This technology makes an electric vehicle's battery pack an interchangeable unit: "6 Reasons Tesla's Battery Swapping Could Take It To a Better Place."

Having an electric vehicle battery at home being recharged during the day allows energy in the battery to be partly discharged at times when spikes in the energy demand exceeds the output of the solar PV system, such as an air-conditioning turning on for 20 - 30 minutes late in the afternoon to cool the home before the residents begin returning from school and work. 

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Another approach

Vanadium flow batteries can be charged and discharged almost indefinitely with little loss in capacity. They weigh more than lithium-ion batteries holding the same amount of energy so they are more suited for fixed energy storage than for powering vehicles.

Instead of using an interchangeable lithium-ion pack to store solar energy during the day and swapping it with a discharged lithium-ion battery pack in a car, a vanadium flow battery could be charged with solar energy during the day and the stored energy could recharge a car's lithium-ion battery pack overnight.

Factor in replacement costs for batteries. #vanadium #energystorage has a 20+ year life span without degradation. pic.twitter.com/N91baBLtjZ

— VSUN Pty Ltd (@vsunptyltd) August 26, 2016