Forget Efficiency and Demand Response, Load Bank for the Grid
Tuesday, March 29, 2011 at 10:32PM
Toby Considine in Electric Cars, Energy, Markets and Innovation, Microgrids and Distributed Systems, Re-thinking things, Zero Energy Buildings

All the Smart Grid attention is on Demand Response, that is, on the half dozen times a year when the grid runs out of energy or has to turn to expensive energy sources. All the building attention is on efficiency, using the least energy inside the building possible. Neither approach supports renewables, or distributed energy resources. Efficiency may reduce the ability to respond to Demand Response signals. Buildings should turn to productive load banking instead.

When I am at home, my smart thermostat turns my home temperature up and down. In the winter, the temperature setting goes way down at night. The house becomes parsimonious just as the local wholesale power market goes negative. The price goes negative because it is expensive to turn up and down the power generation. I don’t see wholesale prices, so efficiency is what I do for now. In a better market, I would increase my use at night, and turn the temperature down when I get up. Instead, I efficiently use more energy by using it at the wrong time.

Load banks are familiar to those who test and install generators. Generators can burn out the circuits they are on, or the equipment on those circuits, if there is not adequate load to consume the power generated. Load banks are paired with generation to use any excess energy. Most load banks do little more than heat the air to burn off excess energy. If we can make our building systems create value while load banking, we will turn grid economics upside down.

Renewable energy, or rather intermittent generation, often generates energy when there is no market for that energy. Wind farms often produce far more energy than they can sell at that time. Just google “wind farm Texas toaster” for description of the problem. The problem is not, as many decry, subsidies. The problem is lack of markets. With no place to sell enough power when the wind is blowing, the great Texas toaster load banks wind power into heat.

Building systems should look at what they can do to use more energy, but at the right time. Ice Energy, which chills water at night to avoid air conditioning during the day, is better thought of as a daily load bank. The real impulse behind utility support of electric cars is that if charged only at night, they provide load banking while expanding their market.

I always laugh when I go to a conference “powered by wind”. I know that they are paying un-economic fees to a power source that is not the wind, which promises to buy wind at some later time. If you want to encourage renewable energy, you need to buy it when it’s available and cheap, not on some pretend market which sells you conventional power, and promises to buy wind later when it is not needed. If we instead bought energy when the wind is blowing, we would increase the value of wind energy. I the great wind farms could sell more than 40% of what they generate, they would be instantly more economic, without waiting for new technologies. Think of it as canning fresh tomatoes in summer. You don’t can tomatoes in summer to heat the house; that would suggest canning in winter. You can tomatoes in summer because that is when they are fresh and cheap.

The most efficient place to store energy is in the middle of a process you were going to do anyway. Ice Energy is effective because it stores cold in the middle of the air cooling process. My home well would be a great load bank if I had a means to store several days of water pressure. A maker of home water heaters marshals thousands of home units to provide fast 4-second load banking to meet the needs of the gird—and radically changes the net cost of water heating. Load banking that performs a useful service creates value you can see every day.

Look at your buildings, and ponder, what you can do in advance, and do it when there is a load banking opportunity. Look for ways to productively load bank your distributed energy resources rather than sell excess to the grid. Look for ways to use more energy, right now.

Demand response happens now and then. For the last couple years, with a down economy and lower industrial demand, it might not happen at all. Load surplus opportunities happen every day. If your building systems can take advantage of this surplus, consume energy when it is cheap and plentiful, to provide service when it is expensive and scarce, you can find new value streams from energy engineering, renewable energy, and building systems.

Article originally appeared on New Daedalus (http://www.newdaedalus.com/).
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