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Sunday, April 1, 2018

Electrical demand balancing

Electricity generating companies are facing a couple of problems which can be solved by demand balancing but first, what is demand balancing.

At present, most generating companies monitor the use of electricity and as demand goes up, bring on more generators and as demand goes down, reduce the power output of generators and even shed them.  All generators have a certain range of output so as power demand increases, smaller variations in demand can be met by increasing the amount of power produced by a given generator but beyond a certain level, more generators must be brought on line Power companies have a dilemma in that they must have sufficient generating capacity to meet peak loads.  This is expensive.  To build new generation capacity when it will only be used occasionally is a nightmare to their accountants.

There are peak generation periods such as in the morning when everyone is getting ready to go to work or school and more so in the evening when everyone is home, the TV is running, mom is making dinner in the oven, it is winter and all the lights are on.  What the generating companies don't need is that at this peak load time you are also running the dish washer, cloths washer, cloths drier, water heater and so forth.  If these functions could be shifted to late at night when all the evening activity is over and the lights are out, then they could avoid having to build more 'plant' that will only be needed in peak hours.

This is where demand balancing comes on.  The power company has to find a way to induce us to use power whenever possible in trough hours so that we don't need this power in peak hours.  The inducement is simple.  The make power less expensive during trough demand.

They could simply make power less expensive for all uses as demand goes down but what is really the holy grail for them is to be able to switch on and off some of your electrical devices as needed to balance their base generation.

We need some hardware and soft ware to make this happen.  Here is an idea of how it will work.

You have special little units that you plug into your wall socket and then plug your device into the unit.  It 'talks' to your smart meter you have installed.  You can set the unit to come on at different prices for electricity and, of course, the power company, when they have a little excess power, will send a message down their lines that now power is at 24c, 23c, 22c and so forth as they need more demand to balance the base power they are producing.

You are unlikely to put one of these devices on your TV or stand up lamp.  If you do, the TV and/or the lamp will go off if the price for power goes above what you have selected. All these functions that are on demand.  ie that you can switch on and off as you want, you still pay the full power price of, let's say, 25c/kWh.  The only equipment you are likely to use these special plug in units for are your chothes and dish washer, any batteries you are charbing (such as your car or wall unit), your hot water cylinder and so forth.  On the front of the device will be a dial that you turn to the price you are willing to pay for the function in question.  But all devices are not equal.

With your car battery or hot water cylinder, the power can go off and on as the power company adjusts the price to use their base generation.  Your washing machine is something else.  Once the cycle starts, you want it to finish.  Otherwise you may have food baked on to your dishes or a wet mess in your clothes washer.  So we have another wee switch on the device which you can put in 'continue to the end' or intermitent.  Now we have one more problem.  For your dish washer, you will set the 'continue' function so once it starts it will finish.

A battery or water heater is something else again.  You may have set your car battery charging unit to, say 10c since past experience shows that you are likely to get some power at this price during the night but here we have a different problem. You want to be able to get to work in the morning.  so we need one more function in our wall plug device..

We have a timer on the device which you set so that full power comes on, say, an hour before you go to work.  If the battery is fully charged, it will not take any more power but if the battery is only partially charged, it will fill up your battery at the full cost.  Not to worry.  Even at the full day time rate, it costs about a third as much in fuel to drive a km than with fossil fuel.

Despite what you hear, power companies are more worried at present by the decrease in power demand.  People are putting in LED lights, factories are becoming more efficient and the power companies are seeing decreasing revenue.  The Electric car is a god send to them.  But they don't want to have to build generating plants that only work to take care of peak demand.  By shifting demand to off periods, they solve this problem and make existing generators much more revenue efficient.  For instance, when there is lot's of water, they can send more of the water through the generator rather than over the spill way.

This is also a great way to help solve the problem of intermitent generation of renewable energy.  Say that during the day, the generation of wind energy is unusually good.  They can lower the price for these special functions such as heating the water in your cylinder even during the day.  You get cheaper power, they sell the excess instead of wasting it and over all, less fossil fuel is used.  Win win all around.

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