MicroCSP – the Other Solar

Background
Hawai‘i, like many other states, has an energy policy that calls for reducing dependence on imported fossil fuels by increasing energy efficiency and the use of renewable energy resources. Despite innumerable plans and studies of energy options over the last three decades, Hawai’i’s dependence on imported fossil fuels has actually increased. This is partly due to the closing of sugar plantations, which burned bagasse for energy. It is also partly due to the cost and pricing structure of alternative energy compared to imported fossil fuels, and the way energy production and sales are regulated in Hawai‘i.

It is clear that to attain a preferred energy future for Hawai‘i, a collaborative effort of government, business, and community is necessary. Thus, the University of Hawai‘i convened Hawai‘i’s major energy stakeholders as the Hawai‘i Energy Policy Forum in May 2002. The purpose of the Forum is to develop an energy vision for the year 2030 and to formulate a strategy to ensure its implementation. The Forum is a unique experiment in collaborative energy policy making. It includes representatives of the electric utilities; oil and natural gas suppliers; environmental groups; the renewable energy industry; the state legislature; federal, state and county agencies; the general business community; and major energy consumers (see Forum Members).

The Forum is designed to facilitate discussion of a preferred energy future and the relevant issues and constraints. In addition to the usual energy economics and technology questions, the Forum considers the roles of energy planning agencies, the Public Utilities Commission, and the Legislature in energy decision-making. The intent is to incorporate as many different perspectives and the broadest possible experience into the design of a flexible, forward-looking energy strategy that provides environmentally friendly, renewable, safe, reliable, and affordable energy for the State.

Learn about:
The Hawaii Energy Policy Forum

The Hawaii Energy Policy Forum

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Concentrating solar power (CSP) systems capture the sun’s heat and transform it into electricity. CSP plants have been on line in California since 1984 and are the least expensive technology for making solar electricity.

 

Concentrating solar power plants produce electric power by converting the sun’s energy into high-temperature heat using various mirror configurations. The heat is then channelled through a conventional generator. The plants consist of two parts: one that collects solar energy and converts it to heat, and another that converts heat energy to electricity.

 Concentrating solar power systems can be sized for village power (10 kilowatts) or grid-connected applications (up to 100 megawatts). Some systems use thermal storage during cloudy periods or at night. Others can be combined with natural gas and the resulting hybrid power plants provide high-value, dispatchable power. These attributes, along with world record solar-to-electric conversion efficiencies, make concentrating solar power an attractive renewable energy option in the Southwest and other sunbelt regions worldwide. The solar resource for generating power from concentrating solar power systems is plentiful. For instance, enough electric power for the entire country could be generated by covering about 9 percent of

Nevada—a plot of land 100 miles on a side—with parabolic trough systems. The three types of CSP systems are parabolic troughs, power towers, and dish-engines. Parabolic troughs collect and concentrate the sun’s energy with large, U-shaped (parabolic) reflectors that have oil-filled pipes running along their center, or focal point.

 

The mirrored reflectors focus sunlight on the pipes and heat the oil inside to as much as 750°F. The hot oil is then used to boil water, which makes steam to run conventional steam turbines and generators.CSP is a good choice in today’s unpredictable power markets. CSP uses proven technology. CSP systems can store thermal energy or be combined with conventional fossil fuels to enable them to operate in cloudy weather or to shift power output to peak demand periods. CSP can deliver power on demand, and its power generation methods resemble those already used by the nation’s power industry. CSP is affordable, and it is versatile. Whether for small-scale distributed power generation or for a large-scale power plant, a new CSP system can be brought on line relatively quickly. CSP is a reliable technology. Parabolic trough power plants in the

Southern California desert have sold nearly 7 billion kWh of solar electricity since 1984. Over time, their output has increased by 35%, and costs have dropped by 40%. Because these plants operate in conjunction with gas turbines, they deliver power when it is needed, not just when the sun is shining.

By Diane Gine, Staff Writer
Energy Smart News

Solar One is concentrated solar power project in the Mojave Desert, California. This project was based on the solar power tower technology where reflective mirrors are placed in a field and track the sun, bouncing the sun energy into a central receiver point. These mirrors are known as a heliostat and the heat generated was the working energy for turbine electricity. This project produced 10 MW of electricity.

Solar Two used a molten salt storage to help adjust for cloudy days. The salt storage was 60% sodium nitrate and 40% potassium nitrate. The molten salt also allowed the energy to be stored in large tanks for future use such as night time.

Known also as Central Receiver Systems, these this project is well documented in http://www.powerfromthesun.net/Chapter10/Chapter10new.htm