Living

Solar community network may be option

Regardless of which side one takes concerning No Name Key's source of electricity, everyone benefits from the heightened awareness of what supports the wide range of lifestyles we take for granted until we unexpectedly lose it.

Over the past 20 years, 90 percent of permitted solar home systems in the Florida Keys have been completed by Sea, Air, Land Technologies. The relatively low cost of utility power when compared to solar power indicates that our grid-tie customers are making a choice of conscience, choosing clean and reliable solar energy to augment their lifestyle.

Being off-grid, No Name Key has an equally difficult choice: Support their energy needs with a relatively small investment of a fuel-powered generator or make a more significant investment in solar. Fortunately, the cost of solar has dropped significantly the past few years.

The real line of demarcation is an air-conditioned lifestyle.

I recently designed and built a 2,500-square-foot home using a passive cool design appropriate for the tropics. This design requires five kilowatts of solar energy to support all home loads or, in more conventional terms, a $55 to $65 monthly utility bill. On the other hand, because of its superior thermal qualities, the home could be air conditioned for less than $200 per month, the equivalent of a 20kw solar system.

Herein lies the crux of the matter, a $40,000 (no AC) or $150,000 (with AC) installed solar system.

The majority of homes on No Name Key are generator-based simply because this is the most cost-effective means to support air conditioning. Most of the homes we have worked on in No Name were never designed for air conditioning, but some now maintain climate control with generators running 24/7 in the summer.

This dichotomy of lifestyle underscores the practicality of designing solar systems to make each home sustainable on its own merits. The homeowner is now motivated to design for efficiency and a more affordable solar system.

Surplus solar power can still be linked to a community energy network, as proposed. The homeowner also retains the ability to disconnect his or her link to the community network if it should become disabled or if the relationship with the energy association becomes untenable. Developing an energy management contract addressing both lifestyles could be daunting.

Individual sustainability does not require overhead lines or expensive coral trenching for interconnect power networking, nor does it put at risk the many mature trees that could ultimately lose the trench-dig battle. If a solar community network is what ultimately evolves, it should also be recognized that to support peak load periods, a central backup generator would need to be incorporated along with a sizeable battery bank for energy storage when power is not being produced.

A final consideration: Grid-tie solar homes throughout the Keys have the advantage of federal incentives and net metering credits. Their unused solar wattage goes to offset commercial power production, thus contributing to a greener community. This is especially true in the summer when, at less than our year-round population, we experience our highest utility demands to meet our appetite for cold air.

-- Bob Williams, founder of Sea Air Land Technologies, Inc. in Marathon, has been instrumental in the design and installation of renewable energy systems, both off-grid, on-grid and offshore, throughout the Caribbean and Florida since 1980. He holds the first Florida Solar Contractors CVC license in Monroe County. SALT deploys more than 90 percent of permitted grid-tie homes in the Florida Keys.

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