A contingent of state officials, including Governor Linda Lingle, representatives from Hawaii’s electric utilities, and other energy stakeholders traveled to the National Renewable Energy Laboratory (NREL) in Golden, Colorado in late July. The visit served as a follow-up workshop for the Hawaii Clean Energy Initiative (HCEI). Much needs to be done if the State is to reach its goal of supplying the energy demand with 70% clean energy by 2030. Rising energy costs provide a greater incentive to move off Hawaii’s dependence on oil.
The workgroup discussion involved a closer look at various renewable technologies suitable for Hawaii. Some of Hawaii’s natural energy resources include wind, solar, and geothermal heat. Officials conceded that a perfect solution is unlikely, with every option facing a technological, economical, environmental, or cultural issue.
The focus is now on determining the best combination of renewable resources and technologies, and drafting legislation outlining the path to reach the HCEI goal. NREL officials are committed to continue supporting Hawaii in its mission by offering various tools and expertise along the way. The contingent also toured the facilities at NREL, allowing for a first-hand look at renewable technologies and research.
Look for continued updates on the HCEI in Consumer Spotlight and also visit: www.hawaii.gov/dbedt/info/energy/hcei/
Solar thermal collectors, photovoltaics…What’s the difference? Since both are mounted on rooftops and use the sun, they are the same, right? Not quite. Although both are used for electricity, they operate differently.
Solar thermal collectors consist of panels used to collect and concentrate sunlight to generate heat. The most well-known of these solar thermal collectors are the flat plate collectors, which are mounted on rooftops for solar water heating. These flat plates consist of an insulated box with a black metal absorber sheet and pipes that run under the sheet. These pipes contain water, which is heated by the sunlight absorbed by the plates. The heated water then goes into a collection tank to be used immediately or at a later time.
Other types of solar thermal collectors include parabolic troughs, parabolic dishes, power towers, and solar pyramids. These types of collectors are used to generate electricity. The solar power plants, on which these solar thermal collectors are found, are usually located out in the desert, where there is lots of sunlight and room for the collectors and power plant. Hawaii-based Sopogy, Inc. has gone a step further by developing their own collector, MicroCSP, which is more apt to Hawaii’s conditions.
Photovoltaics (PV), on the other hand, convert sunlight directly into electricity without the need to heat water and produce steam the way solar thermal collectors do. Photovoltaic cells are made of silicon wafers, which are then connected together to form photovoltaic modules. These modules are electrically connected to form photovoltaic arrays in order to produce enough energy for homes and businesses. When PV systems are connected to a power grid, the electricity produced can be sold back to the utility via a net metering agreement. One benefit of PV is the ability to generate electricity even when it is slightly cloudy.