Electric and Water Heat – Waggaman, LA
64/80 Drainback SWH and 2760W Standard PV
This multi-technology system located in Waggaman is a good example of applying multiple solutions to make optimal use of a solar investment.
Solar Water Heating (SWH) +
Solar Energy System
- Drainback Solar Water Heating System
- 64 Square Feet of Solar Collectors
- 80 Gallons High-Insulation Solar Storage
- Drainback Heat Exchange Unit
The homeowner also concurrently arranged for other energy efficiency and clean energy improvements to the home to maximize the impact of the solar generated energy.
The Drainback Solar Water Heating system produces 80 gallons or more of high-heat water on sunny and even partly sunny days. Distilled water is pumped through two 4′x8′ rooftop Solar Thermal Collectors, directly absorbing the Sun’s radiation and returning heat to the exchange unit. The exchange unit then transfers heat into tap water in the 80 gallon tank using two small internal pumps.
Solar water is stored at very high temperature and brought down to 120 degrees using an adjustable safety mixing valve before entering home plumbing. A backup electric element and timer are used to provide hot water at critical hours in case of inadequate solar exposure, although a solar-heated tank can often provide 2-3 days of water without needing auxiliary heat.
In general, this SWH system provides 70-80% of the homeowner’s water heating needs throughout the year, using solar energy alone. The system requires little or no maintenance, and is not susceptible to freezing due to its drainback design.
Solar Photovoltaic (PV) +
Solar Photovoltaic System
- 12 SolarWorld 230 Modules
- SMA SunnyBoy 3000 Inverter
- 2760 Rated DC Watts
This PV system is a standard Solar Alternatives install, using a triangular layout to match the available Southeast roof surface. The Triple-rail Unirac SolarMount racking system means a solid roof attachment highly resistant to even hurricane-force winds, while flashed standoffs underneath provide long-term waterproofing. A specialized, flashed transition unit allows wiring to discreetly hide from view while maintaining roof integrity.
The 2760 Watt PV system produces approximately 3400kWh per year at this orientation, or about $375 per year at current rates. This dollar value will increase year after year as the cost of electricity rises.