Concentrator Photovoltaic Solar Generator Presented by Max Goldberger Hawaii County Economic Opportunity Council (HCEOC)

Description of the System  The concentrator photovoltaic system simultaneously generates electricity and hot water for household use thereby eliminating water heater and drastically reducing cost for household electricity by conventional method.  When distributed generation units are attached to the electrical grid, it has the potential to sell excess energy back to the grid.

 To facilitate the market, laws currently require the utility company to allow systems up to 50kW to use net metering, with cumulative net metering agreements kept below 0.5% of the utility’s peak demand.  Increasing the net metering standards would allow more photovoltaic installations to sell power to the grid. This must be balanced with the need for the utility company to effectively utilize the intermittent generation.

Photovoltaic Components  Array – 7’ X 14’  Aluminum Channel for Water  Fresnel Lenses  Concentrator Cells  Sun Tracking System  10 Storage Batteries  Total Cost for 3,000 watts (3kW) = $9,600

Electricity Generation Component  The core of the components is the triple junction solar concentrator photovoltaic cell manufactured by Spectrolab, a subsidiary of Boeing.  Cell has a 30% efficiency rate compared to conventional type photovoltaic which has percent efficiency.  One concentrator cell produces 15 watts.

 Fresnel lens intensify to 500 suns radiation at the focal point of each concentrator cell that will produce 15 watts per cell.  One concentrator cell requires one fresnel lens of approximately 500 sq. centimeters. These cells and fresnel lenses are arranged to form an array of 2.25 meters X 3.5 meters with a total of 200 cells and fresnel lenses.  The array of cells requires a tracking system.  The photovoltaic unit will be connected to ten 24-volt storage batteries capable of storing 15kWh electricity for use from sunset to sunrise of approximately 14 hours with 3kWh in excess for reserve power.

Water Circulation Component  Cold water 25 o C (77 o F) will flow through a channel to cool the concentrator cells and the heated water exiting the array of 200 cells at 60 o C to 75 o C (140 o F to 167 o F) will be re- circulated for reuse after passing through a radiator for re-cooling to 25 o C (77 o F).  Hot water for household use is retrieved prior to hot water entering the radiator for cooling and stored in a holding tank of 120 to 180 gallon capacity at about 75 o C (140 o F).

Market Research and Evaluation  With a housing shortage of 5,000 homes currently existing, housing development has become one of the top priorities of the State and County governments. We make a strong assumption that our system will be in high demand for new homes once production begins.  Customers: Residents living in homes outside the utility grid and residents connected to utility grid to take advantage of net metering (pay utility company only the excess electricity used beyond kWh generated by homeowners private electricity generating system).

Benefits  Simplicity of construction with minimum service and maintenance once placed in operation.  Unit is compact, light, and can be easily transported and assembled.  After amortization of initial capital cost, no further costs are entailed, as solar energy is free.

 Economic and Community Development: New industry is established. Improvement in the living environment, socio-economic conditions will improve, generating economic activity contributing toward total community betterment.  Numerous tax credits and rebates available to make renewable energy technology investments affordable.

State Tax Credits for Renewable Energy Systems Solar Thermal WindPhotovoltaic Single Family35% or $2,250 20% or $1,500 35% or $5,000 Multi-Family35% or $350/unit 20% or $200/unit 35% or $350/unit Commercial35% or $250,000 20% or $500,000 35% or $500,000

Promotional Plan  HCEOC acquired a dollar-a-year lease for a 2,100 sq. ft. piece of land at the Natural Energy Laboratory of Hawaii Authority (NELHA) Gateway Energy Center to demonstrate our concentrator photovoltaic solar energy system to the public.  Friends of NELHA (FON) is also interested in working with us to include our project in their weekly presentation and tours.

 In order to demonstrate the effectiveness of our photovoltaic unit at NELHA, we have erected a small house that will be equipped with household appliances such as a refrigerator, television, air conditioner, lights, water tank for hot water, and storage batteries to be charged for night- time electricity use.

Array Tracking System

Demonstration Hale