Sunday, November 18, 2007

Options to Address Energy Issues

Where should we be spending our climate change dollars? Generally, the energy generation systems we use are woefully inefficient. A steam-based subcritical fossil fuel power plant can achieve 36–38% efficiency, with supercritical designs reaching efficiencies in the low to mid 40% range, and new "ultra critical" designs using pressures of 4,400 psia (30 MPa) and dual stage reheat reaching about 48% efficiency. Of course, most plants are in the lower ranges of efficiency, with minimal gains since the late 60s. So, most of the energy that goes into the plant in terms of coal, natural gas, biomass, etc. does not end up hitting the distribution network, it goes up the smokestack. That certainly smells like an opportunity to apply systems thinking to recover some of that energy.

The latest issue of Orion Magazine has a short piece by Bill McKibben on the potential for waste heat recovery to combat climate change in centralized power plants, The Unsung Solution.
Here's an excerpt from Bill's article in Orion that illustrates one of the challenges facing recovering waste heat as part of an energy efficiency effort nationally:
For instance, in almost every state it’s illegal for anyone but the utility to run wires across a public street. So if Casten’s company generates more electricity from the smokestack of the coffee roaster than the factory can use itself, his company can’t sell the surplus to the guy making coffee cans across the street. They have to sell it to the utility, which wants to pay the lowest price possible for it. The utility argues that it still bears the cost of maintaining the network of wires that constitute the grid, and if it’s not selling to the coffee-can plant, that cost will have to be passed on to, say, residential customers.
So, due to the existing regulations, there is little the energy recycler can do to engage in the sale of the power they're producing? Bill goes on to say that environmentalists will need to include technologies like this (un-sexy as they are) in their efforts, instead of completely focusing on windmills, solar panels, and biogas digesters exclusively.

It certainly makes sense to work on the efficiency elements of the equation instead of the creation of new energy sources. The folks at the Rocky Mountain Institute have been lobbying for efficiency improvements since the mid-70's, here's an excerpt from a report written in 1990, The Negawatt Revolution,
Energy efficiency ultimately represents a trillion-dollar-a-year global market. American companies have at their disposal the technical innovations to lead the way. Not only should they upgrade their plants and office buildings, but they should encourage the formation of negawatt markets. And they should let the United States Government know that the best energy policy for the nation, for business, and for the environment is one that focuses on using electricity efficiently–for it's the only policy that makes economic sense.
What we're getting at is looking at our existing systems and optimizing them. This just makes sense. The barriers are certainly large, especially since power producers are in the market of selling kW-hrs. They may have energy efficiency programs, encouraged by government regulations, but are they really interested in selling less power?

Another player in the effort to create a more efficient energy infrastructure is demand response. If energy use is driven by demand, why not reduce the demand? Turn off the lights when they're not needed, switch to more efficient motors, optimize use in real time. One company that has attacked this opening on the industrial side is EnerNOC. Based here in Boston, EnerNOC currently manages about 900 MW of "demand". In the event of a high demand event, say a very hot day or a very cold day, EnerNOC, through its network of customers managed with its technology, can reduce demand in as little as 30 minutes. Their clients agree to allow parts of their business (things that will not affect the operations of the company) to be turned off, throttled back, or even turned on (like back up generators) under EnerNOC's management to help the utility meet the region's demand. What does this mean? Less power is needed, and potentially, when tied into the smart grid of the future, the need for many thousands of megawatts in new generation facilities could be avoided. It works because the clients earn money by supplying power to the grid, EnerNOC makes money as the matchmaker, and the grid operator saves money (potentially lots of money) by avoiding the purchase of high priced peak power. Winning all around.

All of these tools contribute to the reduction of climate changing CO2 emissions, reduce costs associated with electricity generation, transmission, and use, and moves us ahead in our thinking of what our energy systems should be.

No comments: