Prospects for Solar Energy for Major Residential
and Commercial Developments in Chatham County

prepared by Jack C. Star  jack@solarsavannah.com  233-4288

     The State of Georgia lags far behind many other states that use a combination of grants, rebates and tax relief to develop a solar energy infrastructure. Despite this lack of incentives, however, the current and projected near-term costs of solar installation have dropped to the point where developers, builders, architects, and planners need to incorporate some form of solar energy in all future construction. Otherwise, new construction, with a useful life of over 50 years, will continue to drain energy, rather than being energy neutral or even energy producers.

     Solar installations can be incorporated in each structure and also on “solar farms” -- acreage specifically set aside to provide electric power for a community or subdivision. Current technologies employ either roof-mounted solar thermal or solar voltaic panels to heat water or provide electricity for individual structures. A variety of solar concentrators, approximately six to an acre generating from 150 kW to 180 kW per acre (enough for 36-40 residence units), provide even less expensive electricity. Economies of scale in manufacturing, plus the development of new technologies, will start bringing prices down dramatically within a few years.

Individual Structures

     Solar panels that heat water for residential and commercial use, as well as for swimming pools, are currently justified on all new construction. Payback varies from 3 to 8 years for units that have a useful life of 20 years. Residential energy costs would be cut from 10 to 15 percent.

     The cost of solar panels that turn sunlight into electricity have dropped from $100 per watt to less than $6 per watt and are projected to drop further to less than $3 per watt within four years. However, as can be seen in Canada, Germany, Portugal, Spain, Japan and Australia, as well as California, Connecticut, Massachusetts, Rhode Island, New York, New Jersey, Ohio, Arizona, Nevada, New Mexico, today’s higher costs can easily be justified by reducing pollution from fossil fuels, lowering peak loads, and anticipating increases in the price of coal and natural gas.
[Update: this was prepared in 2005 - Now, Jan. 2008, retail cost of panels has dropped below $4.50 per watt and are expected to drop closer to $2 a watt within a couple of years -- js]

Community-based Solar Power

     Presently, there are four major technologies that will produce electric power at the same level as many power plants (over 300 MW) and at far less cost per kW than roof mounted photovoltaics.

     1) Pole-mounted photovoltaic modules that track the sun.
     2) Dish concentrators. Large dishes with mirrored surfaces that concentrate the sun’s rays on a Stirling engine and directly generate electricity.
     3) Trough concentrators. Parabolic reflectors that concentrate the sun’s rays on a tube filled with a special fluid that can be heated to over 375 degrees C. The heated liquid powers a steam engine that generates electricity.
     4) Fresnel lens concentrators. Giant arrays of fresnel lenses which focus light on special photovoltaic cells resulting in very high efficiencies.

     Presently, solar farms (also called solar fields) built around these technologies, have been, or are being, installed; and more orders are anticipated. Manufacturers state that as they ramp up production prices will fall to as little as $2 per watt, making them competitive with fossil fuels. At the present time, concentrator technology requires substantial acreage to be cost competitive. However, once economies of scale are reached, 30 to 40 acre solar mini-farms will be feasible.

Implications for residential and commercial development in Chatham County

     At the present time local planners, developers, and builders do not appear to be taking into consideration the explosive growth of solar capability that will be commercially available in just a few years. As a result there is no planning for setting some acreage aside to produce electricity within the development. It is estimated that setting aside 3 to 4% of the total acreage of a development would provide nearly half of the electric requirements of the residential and commercial structures, with a payback period of less than 14 years and a useful life approaching 25 years.

     From a solar perspective, the ideal community would draw power from a local solar farm, and each residential or commercial unit would have an individual solar hot water system and about 2 kW of roof or pole mounted photovoltaic modules. This mix of solar sources combined with energy efficient construction, the use of Energy Star appliances, and low wattage lighting could yield a Zero Energy building.

     In addition to the obvious benefits of reduced dependence on fossil fuels, the elimination of greenhouse gasses, and the reduction in air pollution, incorporating solar facilities in local developments will also create jobs and help build a number of new local businesses, and make Savannah and Chatham County an even more desirable place to live.

Potential Tax Benefits in the New Energy Bill

[Update: Tax relief for solar installations has been stalled in the Senate (through approved by the House) and under current regulations extend through 2008. Hopefully the extension through 2012, and the increase in the residential tax credit to $4,000  will be passed this year. -- js]
     Recently, the Senate approved two areas of tax relief for solar installations. One would grant business a 30% tax credit for solar water and solar electric (including solar concentrators), and another would grant a $2000 tax credit to home owners for solar water or solar electric installed on a residence. This is the first time in over 20 years that a credit has been offered to individuals. If these measures are included in the final Energy Bill the implications for local solar energy development are excellent. But preparation must start now.

-- Originally publsihed June 20, 2005