Four Seasons Hotel Philadelphia installed three Capstone C65 ICHP MicroTurbines® - a form of distributed power generation. Image credit:Capstone Turbine
Now that I have succeeded in disturbing a number of engineers and environmentalists, while admitting the difficulty of even defining distributed power (see What Is Distributed Power Generation? for details), it is time to lay out what makes distributed power generation (DP) superior to expanding central power generation. Caveats: 1.) this is about meeting long-term electricity demand growth - in an effort that must span the next four or five US Presidential administrations; 2.) success requires a strong parallel effort at energy conservation; 3.) distribution and transmission networks still need upgrades, but less so if distributed power is widely deployed.I'm brainstorming now. Order does not denote priority or cost-benefit ratio.
You want to post your own ranked list of pros vs cons, go for it.
Key benefits of distributed power generation (DP).
- Proven technologies for DP are widely scalable. Obvious example: a wind farm can be incrementally built in multiples of approximately 1.4 MW.
- Bigger doesn't necessarily mean "cheaper" for DP. Customers can match the DP capacities to precisely known needs and not have to over-buy equipment. (see Figure 1 in What Is Distributed Power Generation? for examples of scale). Quite the opposite for big utility-scale thermal generation plants , which have to design to support all projected growth and pay up front for capital equipment needed for future growth.
- Copper is expensive and dirty to make and string overhead. The mining, benefaction, and smelting of copper ore typically have severe environmental impacts and are very energy intensive - these days the impacts of copper production are mostly felt in developing nations - and anything done to minimize the need to build new transmission corridors or to expand distribution networks helps.
- Expansion of transmission corridors is necessarily going to screw up a great deal of land in parks and national and state forests. Eminent domain will be used to take private homes farms and ranches and people are going to be mad as hell about it. DP can help minimize this.
- All power generation investment poses financial risk. Investment in facilities that produce thousands of mega-watts each, however, can leave much money on the table for a very long time. (Subsidies for big nuclear or for "clean coal" put the burden of financial risk on taxpayers who weren't even alive when the decision was made to invest!) DP, especially small scale projects, allows for more of a pay-as-you-go investment approach.
- Combustion-based DP technology - doesn't matter if it's a coal fired, gas fired, or biomass fired - is of a scale and environmental character that "waste heat" can be cost-effectively put to use in district heating schemes, or for industrial HVAC or processing, or for aquaculture - to cite but a few examples. Putting the waste heat from power generators to use can raise the total fuel efficiency of a thermal DP technology by 30% or more. (Conversely, the central distribution generation units pull in millions of gallons per day of surface waters needed for condensing and cooling. This can simply overwhelm fish and aquatic life in all but the largest bodies of water, while DP units can use storm water runoff to satisfy some of the cooling needs.)
- A municipal Combined Heat and Power system (CHP) system - a traditional and very common form of DP in Europe and North America - can be owned and operated by a community; or, it can be operated by a contract service supplier; or, it can be owned and operated by private investors. DP is, in theory, ideology blind. (Conversely, most central generation facilities are outside their respective municipal areas and only are amenable to ownership by entities capable of taking long-term financial risk.)
- Say you own a business that's energy intensive. Got rooms full of servers, or factories that depend on steady lighting and pumping to keep workers and the surrounding community safe? Mission-critical operations can continue even if the grid goes down from ice storms, floods, or whatever other mayhem you can imagine - if you invest in DP.
Update: I forgot to include an historic overview of electric power development in the USA. When canals and locks were built in the late 1800's, industrial and residential development bordered rivers and harbors, densely. Later, when railroads were built, new towns and factories clustered by the rail corridors, often at distance from major waterways. When the interstate highways were built, new development skipped the rails and rivers entirely for being around the highways and municipal bypasses.
Coal and nuclear plants remain by the rails and major waterways, to take advantage of bulk hauling by rail and barge and/or to get access cooling water. Today's and tomorrow's demand growth, however, is far from those places - stranded away from the water and rails. That's a major reason why DP is positioned to leapfrog central power's grip.