ECONOMICS
Electricity Capital Costs Capital costs are one way a renewable system is judged. Any particular renewable is measured in dollars per Watt ($/W). The higher the capital cost, the more expensive is its initial cost. The Microgrid and the Hectare capital costs for electricity are compared with other ways of producing electricity. “PV + Batteries” has two parts, collectors and batteries. PV collectors from Asia are very low priced, typically $1/W installed. But they only collect sunlight during the day. They require energy storage: batteries that store daytime solar energy until nighttime. A battery set costs about $2/W and only lasts 10 years. The second set lasts another 10 years. To get a 20-year lifetime, the true cost of a PV system is the PV collectors plus two sets of batteries giving a $5/W capital cost. The Microgrid does better than that at $3/W, including collectors, storage and generation. It needs no batteries because heat is stored inside and later converted into electricity. The Hectare electricity production comes in lowest at $1/W because it uses economies of scale to reduce costs. Focused Sun collectors are low cost, storage is site-built and generation is a purchased steam turbine which are produced at low-cost in Asia. By comparison, utility capital costs are also about $1/W for large gas-peaker plants. These plants have replaced coal and oil fired utility generation (fossil fuel plants) in the last few decades. While low in capital costs they are high in operating costs. Their natural gas fuel also varies in price as its demand is high and its supply is limited. |