Project data
Authors User:Mkhultin
Status Deployed
Made? Yes
Replicated? No
Export to Open Know How Manifest
Location data
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Location Arcata, California

A grid tied solar photovoltaic and thermal heating system was installed at a home in Arcata, CA which uses a heat recovery system to heat the home (that includes an expansion tank). Radiant floor heating was installed and heats the floor using hot water in pipes beneath the floor's surface. A solar pathfinder was used to help identify where shading may effect the solar panels efficiency.

On site Photovoltaic & Solar Heating system on Golf course rd, Bayside Presented by Ben Scurfield

This site displayed a grid-tied photovoltaic and thermal heating system. Net metering is used on grid tied systems. This means that the excesses power produced in a given day is sold to PG&E and then bought back when needed at night. PV panels do not produce energy when blocked by shadows such as a tree or structure. For maximum efficiency the Panels should be adjusted +15 degrees in winter and -15 degrees in summer. This house uses a heat recovery system (HRV) which provides fresh air from the outside without losing internal heat. Quick Trex radiant floor heating is used to heat the home. This involves tubing installed on top of the subfloor with hot water running to provide warmth. A solar pathfinder was located at the site. This involves a visual map of the year compared to the shadow an object will project at particular time of day. A clear dome shape plastic reflects the shadow on the map to display how much light will be available at what time of day at what time of year. An expansion tank is needed for a solar thermal heat system to compensate for overheating, steam which can cause a pressure increase. A line or tank can burst without an expansion tank. A stainless steel holding tank is ideal for higher temps. High efficiency appliances are given a 30% rebate. This is an outline of the photovoltaic system:

System overview:

  • 1.9 kilowatt
  • 12 panels
  • Inverter: Sunnyboy
  • 240 volts

Power produced:

  • 8 kilowatts per day on average


  • $20,000


  • 20% efficient panels
  • 95% efficient in conversion in inverter
  • <1% line loss