In the ongoing effort to improve efficiency while reducing greenhouse gas emissions, many large residential and commercial buildings are studying co-generation as a means of accomplishing both goals. In essence, co-generation signifies getting two forms of energy from one process. Blackouts, brownouts, and increasing demand on a weak utility infrastructure are causing many large cities to promote co-generation. Many complexes see it as a way to save themselves and their residents money on utility bills.

What is it?

Most buildings get their energy from the power grid, mainly through natural gas or oil-based systems. During the process, a lot of energy is lost, usually through steam. The idea of co-generation is to get two thermal energies from the one product. For instance, when a system produces electricity, oftentimes steam is released during the process. That steam can then be captured and used to provide water or space heat for the building; significantly cutting down on energy costs.

Rarely do co-generation projects provide all the energy needs for a building, but they can make a sizable dent. In addition, according to The Cooperator, a co-generation system is not for every building. There are several factors that must come together to make the project worthwhile, most notably the size and load factor of the building. New York City, led by Mayor Michael Bloomberg, has become a major proponent of co-generation in its effort to reduce the city’s carbon footprint.

Benefits

The most blatant benefit of co-generation is a reduction of energy costs, lower emissions, and the advantage of using readily available energy that previously went unused. The rate of payback for co-generation systems depends on the size of the system and the proper sizing of the system. Penn South, a co-op in NYC, claims up to $700,000 in utility savings annually. That community has nearly 3,000 units. The systems use grid-based, fossil-fueled energy; they merely increase the efficiency and lessen the waste of that system. Nonetheless, some cities treat co-generation as a renewable energy system.

Co-generation systems may also have the ability to work off the grid, a major advantage in the event of a blackout. Some systems can be started independently of an outside energy source. Again, it all depends on the type of system.

Drawbacks

Up-front costs are cause for reluctance for communities considering a co-generation project. They can be quite sizable – the average cost is around $1,500 per kW. A system for a 100-unit building could cost up to $300,000, says Damian Sciano, project manager and engineering ombudsman for Con Edison. It’s a lot of money to spend, considering systems are rarely self-sufficient, energy prices are extremely volatile right now, and in the face of emerging technologies like solar power.

Speaking of solar power, that brings up another drawback for co-generation, especially for co-ops, condos, and other complexes with a lot of roof space. The solar industry is growing fast and has a more likely long-term benefit than fossil-fueled energy systems, co-generated or not. Indeed, the idea of community solar power is not new. The prospect of long-term, renewable opportunities is an important one for co-ops.

After All

Nonetheless more buildings are co-generating these days, after all it makes sense. Why let so much energy go to waste? It may be exceedingly beneficial for buildings that need some sort of mechanical overhaul anyway. It seems that the larger the building, the more a co-generation system would be beneficial. Yet the consensus seems to be that all avenues should be searched, and this uncertainty seems to be stalling many organizations and buildings in the rush toward energy efficiency. Regardless, co-generation is on the rise and will undoubtedly make some difference – economically and environmentally.

Source: Leading More Buildings to Co-Generate

Posted on October 6th in Solar Politics by Dan.