Local utilities are among the largest power users in their communities. This is why power companies make agreements with utilities at reduced cost if the utilities will install backup power supplies. The peak power generation capacity as well as backup capacity is at the local utilities and other large users. Power companies can delegate this capital cost to large users without the investment concerns. It works for both parties. In addition, power companies spend effort to be more efficient with current power supplies, because recovering the costs for new, large plants is difficult, and in ways, cost prohibitive. Hence small increment options are attractive, especially when they are within high demand areas (distributed power). The use of localized wind, solar and on-site energy options like biogas are cost effective investments if sites can be found. That is where the utilities come in. Many utilities have sites. Large water utilities may have large reservoirs and tank sites that might be conducive to wind or solar arrays. Wind potential exists where there are thermal gradients or topography like mountains. Plant sites with many buildings and impervious areas could also be candidates for solar arrays and mini-wind turbines. Wastewater plants are gold mines for digester gas that is usually of high enough quantity to drive turbines directly. So utilities offer potential to increase distributed power supplies, but many water/wastewater utilities lack the expertise to develop and maintain these new options, and the greatest benefit is really to power companies that may be willing to provide as much money in “rent” to the utilities as they can save. Power entities obviously have the expertise and embedded experience to run distributed options optimally. So why don’t we do this?
I would speculate several reasons. First, the water/wastewater utilities have not really considered the option, and if they do there is the fear of having other folks on secure treatment sites. That can be overcome. The power entities have not really looked at this either. The focus in the power industry is to move from oil-based fuels to natural gas to accumulate carbon credit futures, the potential for lower operating costs and better efficiency of current facilities to reduce the need for capital investments. Power entities operate in a tight margin just like water/wastewater utilities do so saving where you can is a benefit. There are limited dollars to invest on both sectors and political and/or public service commission issues to overcome to invest in distributed power options at water/wastewater facilities.
But a longer-term view is needed. While fossil fuels have worked for us for the last 100 years, the supply is finite. We are finding that all that fracking might not give us 200 years, but more like 20-40 years of fuel. We have not solved the vehicle fuel issue and fossil fuels appear to be the best solution for vehicles for the foreseeable future which means they will compete directly with power demands. Natural gas can be used for vehicles fairly easily as evidenced by the many transit and local government fleets that have already converted to CNG.
The long-term future demands a more sustainable green power solution. We can get to full renewable power in the next 100 years, but the low hanging fruit need to be implemented early on so that the optimization of the equipment and figuring out the variables that impact efficiency can be better understood than they are now. For example, Leadville, CO has a solar array, but the foot of snow that was on it last September didn’t allow it to work very well. And solar arrays do use water to clean the panels. Dirty panels are nowhere near as efficient as clean ones. We need to understand these variables.
Area that are self sufficient with respect to power will benefit as the 21st century moves forward. There are opportunities that have largely been ignored with respect to renewable power at water and wastewater facilities, and with wastewater plants there is a renewable fuel that is created constantly. Wastewater plants are also perfect places to receive sludge, grease, septage, etc which increase the gas productions. There are examples of this concept at work, but so far the effort is generally led by the wastewater utilities. An example is East Bay Municipal Utility District (Oakland, CA) which produces 120% of its power needs at its wastewater plant, so sells the excess power back to the power company. There are many large wastewater plants that use digester gas to create power on-site to heat digesters or operate equipment. Others burn sludge in on-site incinerators to produce power. But so far the utilities are only reducing their cost as opposed to increasing total renewable power supplies. A project is needed to understand the dynamics further. If you are interested, email me as I have several parties wishing to participate in such a venture.