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Showing posts with label Zigbee. Show all posts
Showing posts with label Zigbee. Show all posts

Monday, May 27, 2013

Getting ready to go off the grid

Suppose you have a solar photovoltaic system or a BlueGen fuel cell home generator and a collection of appliances that can be monitored and controlled automatically by a tablet computer.

A hot water system might be set to keep water between 50°C and 60°C.
  • If the water temperature is at or below 50°C, the water heater should be on. 
  • If the water temperature is at or above 60°C the water heater should be off.
When the water temperature is anywhere between these upper and lower temperatures the status of the heater could be on or off. From your point of view, the status of the water heater ("on" or "off") is "Don't care if on or off".

Refrigerators, freezers, air-conditioners and space heaters can be automatically controlled having regard to:
  • A lower temperature at which the appliance should be "on" (for heating appliances) and "off" (for cooling appliances)
  • An upper temperature at which the appliance should be "off" (for heating appliances) and "on" (for cooling appliances) 
  • For any temperature that is between the lower and upper temperature, the appliance has a status of "Don't care if on or off".
When your home energy system is generating more energy than is required for all appliances that are turned on, extra energy can be sent to some or all appliances that are "off" but have a status of "Don't care if on or off".

A ZigBee HVAC Application
A ZigBee HVAC Application
When your home energy system is not generating enough energy for all appliances that are turned on, energy can be saved by cutting energy being sent to some or all appliances that are "on" but have a status of "Don't care if on or off".

Controlling appliances in this way reduces the size and cost of energy storage.
  • Excess energy being generated is added to any appliance that can use it.
  • Peak energy use is lowered - when more energy is being used than is being generating - by automatically withholding supply from any appliance that can postpone its energy needs.
If your household has an electric vehicle parked in a garage, it can be controlled in an even better way. For example:
  • When the battery charge is below 40 percent, charging should be "on".
  • When the battery charge is at 100 percent, charging should be "off".
  • When the battery charge is between 40 percent and 80 percent, charging can be considered to be "Don't care if on or off".
  • When the battery charge is between 80 percent and 100 percent, the battery can be considered to be "Don't care if charging is on or off, OR if discharging is on or off". (That is to optionally SUPPLY energy to the home.)
Notice that the last status above allows the household to make use of any electric vehicle parked in its garage for energy storage - at no extra cost...

A smart meter is not a requirement to implement such an energy management system.
ZigBee Alliance Integrated ZigBee low-cost controllers in a range of appliances from different manufacturers are a prerequisite.
  • Proprietary communication protocols and energy automation software would make it very difficult and expensive to implement the desired level of control. 

If you are still connected to the grid, this level of control allows you to reduce the peak demand your household makes from the grid. This strategy helps:
  • To reduce the need for network investment in extra poles and wires.
  • To avoid the need for price increases for the electricity that you purchase from the electricity grid.
There are a number of businesses with Zigbee technology experience that could help manufacturers begin to offer versions of their appliances that are "ZigBee-enabled".

For example:

Saturday, September 29, 2012

Grid-Friendly Appliances

Their time has come. Appliances that soak up electricity from the grid when it is convenient, and stop feeding when the grid has limited capacity to meet other pressing demands.

Efficient appliances are recognisable by energy-star ratings. There is no way to recognise a grid-friendly appliance.
Grid-Friendly Appliances
Grid-Friendly Appliances

"Aren't more efficient appliances grid-friendly?"  


Well, no. At least not necessarily. A more efficient air-conditioner may only need 4 kilowatt-hours to do the same job that an earlier version required 5 kilowatt-hours to do. A 20 percent improvement. Now if the earlier version used 5 kilowatt-hours over a 24-hour period and the new model insists on receiving 4 kilowatt-hours all in one 30-minute gulp right in the middle of a peak demand period, then the more efficient air-conditioner is most definitely less grid-friendly than the previous model.

"How exactly will grid-friendly appliances help?"


Grid-friendly appliances first and foremost help to reduce the cost of supplying electricity by providing a flexible load. When extra generating and transmission capacity is unused during off-peak periods, grid-friendly appliances will provide a market instead of allowing that capacity to go unused.

When the breeze suddenly drops and a wind-turbine farm output falls, the grid-friendly appliances will drop out and avoid the cost of backup generators to fill in.

"What would make a good grid-friendly appliance?"


An electric vehicle being recharged over an extended period from a smart power point is a good candidate for a grid-friendly appliance. It stays in its garage or parking spot connected to the electricity grid. It won't care if charging is deactivated from time to time, or that charging is enabled by an external signal when capacity becomes available.

Another candidate would be an air-conditioning system that creates and stores a large quantity of ice that it makes whenever it is convenient for the grid to supply it with electricity. The air-conditioning of buildings and homes of the owners proceeds without interruption because only a very small amount of energy is needed to deliver cooling from the ice-store. A hot-water storage system is a similar candidate for a grid-friendly appliance. A heat pump is a more efficient hot-water system than a resistive heater, but both could be equally grid-friendly.

"Do we need changes to market rules and standards?"


There is some experience with market rules and standards that help identify where changes can assist in promoting grid-friendly appliances to achieve the objective of reducing the cost of energy.

The energy-star rating standard that identifies energy-efficient appliances is a model that could be adapted for a new "grid-friendly rating" of appliances.

Queensland and Western Australian electricity retailers have experimented with offering electricity discounts to customers who install demand-responsive air-conditioners. This is a model that can be used to encourage the take-up of grid-friendly appliances

The next examples point to a minor failing with an aspect of the electricity market: The disappearing price signal. A major electricity grid owner recognised a cause of inefficiency in the use of its infrastructure, and set a high price to send a clear price signal to encourage large energy consumers to remedy it. However, these energy consumers had supply contracts with retailers who just passed on the "price signal" from the grid owner but did not give the customers the information they needed to assess if they were able to do anything about responding to it. One customer looking for a solution to a completely different problem stumbled by serendipity upon this hidden price signal. The result: an immediate$10,000 investment by the customer in a device to solve the grid owner's legitimate concerns over inefficient grid use. The ensuing $5,000 reduction in the customer's annual electricity bill, was the intended response to the grid owner's "price signal". This example is written up in the post The other smart meter hazard.

A similar situation is developing with "grid-unfriendly" appliances. Major electricity grid owners are proposing a "price signal" with dynamic charges to increase the cost of electricity during times of grid stress so consumers will be "persuaded" to turn off appliances. After one trial a grid owner considered that a dynamic charge of about 70 cents per kilowatt-hour is needed to get consumers to turn-off "grid-unfriendly" appliances. This trial is written up in the post Get Ready for Electricity at 70 cents per kWh.

This proposal  cannot begin until after the roll-out of smart meters in an enormously costly and time-consuming project. This approach was adopted by the former Victorian State Government in Australia. This is not exactly the same as the "disappearing price signal" example above. Instead it leaves consumers receiving the price signal, eventually, but being at a loss to find a satisfactory way to respond. It is also very expensive to install smart meters universally. This undermines the purpose which is to reduce the cost of delivering energy.

An alternate strategy with lower costs and inconvenience is to offer smart meters to consumers at the time they choose to install grid-friendly appliances. This allows Time Of Use (TOU) charges to reward these consumers with discounted energy for helping to reduce grid infrastructure costs: More carrot, less stick.


Thursday, September 6, 2012

Invitation: Go5 Launch with City of Melbourne

Event: Make Your Home Energy Smart  
13 Sept|6 - 8pm| Melbourne


You're invited to 'Make Your Home Energy Smart' - an event hosted by The Australian Alliance to Save Energy and the City of Melbourne.

The City of Melbourne will launch the Go 5 campaign on the night. This initiative gives residents information about how much energy an average home uses and helps them reduce their electricity consumption to 5kWh of power use per person per day (or better!)

Chris Dunstan,  CEO of the Australian Alliance to Save Energy, will be discussing what is driving up energy prices and what residents can do about it.


This event is free to attend but places are limited.

Date: Thursday, 13 September
Time: 6:00pm - 8:00pm
Location:
Swanston Hall, Melbourne
Town Hall, 30 -130 Swanston Street,
Melbourne, VIC 3000
 

Link to online map

Speakers:
- Chris Dunstan, CEO, Australian Alliance to Save Energy
- Amandine Denis, Head of Research, ClimateWorks


RSVP & more information  

Sunday, August 26, 2012

Team Work on Energy Costs

Beef Exports, Technology Imports and the High Australian Dollar


Australian beef growers can get better returns and their overseas customers a better deal if energy costs can be cut for a firm at the front line of beef exports.

The high Australian dollar is a two-edged sword. On one hand Australian exports are more expensive. On the other Australia gets good value for money on high-technology purchases that can be used to reduce costs and increase profits.

Finding overseas suppliers for equipment and developing ongoing business relationships has further important benefits for all parties. There is a two-fold benefit when Australia can find good sources for equipment from its trading partners. This supports the momentum in their economies. It maintains Australia's customers purchasing power for buying its exports.

It helps to counteract the slowing of economic activity in Australia's major trading partners such as China and in Europe that reduces the demand for Australian exports.

A business that is a staging area for beef exports has extensive cool-rooms and freezers with very high energy requirements. The carbon price is a significant impost as is the rapidly rising cost of electricity distribution in Australia.

The challenge and opportunity is to find cost-savings with commercially viable energy supply and automated management technology.
HACCP Food Safety Management Programmes
HACCP Food Safety Management Programmes

Systematic international food safety management in the industry in accordance with "Hazard analysis and critical control points" (HACCP) may be simplified if automated energy management technology can tackle part of the compliance costs for record-keeping. Automating alerts and responses when any cool room temperature deviates from what is required could avert product spoiling.

Energy Generation Technology to Cut Costs

VitoBloc CHP unit Module EM-401/549
VitoBloc CHP unit
Module EM-401/549
Retail energy costs in Australia are especially high by international standards as a result of massive investment in the distribution grid. The carbon price that commenced on July 1, 2012 has added to this cost.

These costs make the goal of commercially viable local generation an easier one to achieve.

Generating energy locally tends to be cheaper per kilowatt with larger systems. This means that larger systems such as the recently installed trigeneration plant at Coca-Cola Place in North Sydney are proving to be commercially viable. A generation system for a single residential household is more difficult to cost-justify.

Establishing commercial viability of generation systems suited to medium sized businesses with multiple sites is getting easier. Continually growing retail energy prices and advances in technology both make this problem easier to solve.

A business paying about $1,200 a month for carbon dioxide emissions for electricity from coal-fired power plants is using about 60,000 kilowatt-hours each month. (The carbon price for coal-fired power is nearly 2 cents per kilowatt-hours.)

In broad terms a local energy generation system can be used to produce electricity to supply about half of the energy needed for cool rooms and freezers. The "waste heat" from the generation system can be used in absorption chillers to supply the other half of energy needed for cool rooms and freezers.

Savings from the system come from four sources:

  • Fuel is used far more efficiently than in large central power stations.
  • The carbon price is not payable by any enterprise emitting less than 25,000 tonnes of carbon dioxide per year.
  • The amount of carbon dioxide emitted is much less than that from a coal-fired power station even if any carbon price becomes payable. About 75 percent less.
  • The major cost component - the infrastructure to transmit power from large central power stations - is not avoided. It is not only the owner of the local generation system who saves money; Electricity grid investment is avoided and this bestows a benefit on every energy consumer.

Potential suppliers may be easier to find in Europe where local generation is more widespread than in Australia. One example is the German manufacture Viessmann Group that builds Vitobloc combined heat and power units. These power generation systems are manufactured in a range of outputs so matching the technology to different businesses' energy requirements is not too difficult.

Automation Technology to Cut Costs

A small number of businesses have designed and created a huge range of wireless sensors, controllers and information systems that build upon internet and smart phone technology. These new devices have enormous potential in many areas of home life, agriculture and industry.
Wireless irrigation system
Wulian Sensors and Automation Technology

Safety, health and comfort of the elderly and people with disabilities living in their own homes is just one of many areas where this technology should be applied sooner rather than later.

Another area is in monitoring and controlling the operation of business equipment such as energy generators, freezers and cool rooms. All operations can be continuously monitored and controlled according to an automated schedule. Alerts where any unusual situation arises can be immediately notified via the internet to any smart phone. People can send instructions over the internet with smart phone apps to remotely control business machines and without needing to travel to the business premises.

One of these businesses is Nanjing IOT Sensor Technology that has developed a great many different devices and software. The slow-down in major world economies is making business conditions difficult for such innovators. An Australian business could benefit by establishing an ongoing working relationship with such a supplier, providing feedback and design ideas to tailor products to best suit its needs while at the same time helping create wider awareness of the benefits this innovative technology provides.