Home scale solar installations

Discussion in 'Environmental' started by BillLin, Feb 7, 2020.

  1. BillLin

    BillLin PV solar, geothermal HVAC, hybrids and electrics

    Please feel free to add to this post with details of your solar installation.

    Related thoughts on home energy use reduction are welcome as well though if there is another topic already started elsewhere, I'll add to that instead.
    xcel likes this.
  2. BillLin

    BillLin PV solar, geothermal HVAC, hybrids and electrics

    Location: North Central Massachusetts USA
    System: 40 ground mounted 250W solar panels feeding 40 Enphase M215 microinverters; net metering
    Home: 2200 sqft modified Cape contemporary home; 2x6 frame construction; well insulated; heavy vinyl siding; metal roof
    Heating/Cooling: ground source geothermal heat pump running completely without use of AUX heat (resistance heating)
    Hot water heater: heat pump water heater set to run entirely in heat pump mode

    In other words, we rely on electricity for everything. The oil heating system we removed when we went geothermal used to consume about 500 gallons of fuel oil a year. Our total electricity usage is now about the same amount of equivalent energy or less.

    Weak points: cloudy days and ice/snow fall ; I diligently clear off snow usually the same day or the next day, so snow losses are minimal compared to my neighbors with roof mounted panels.

    Future: increase PV solar system and add battery storage

    The solar setup in my profile photo generated 540 kWh in December and 797 kWh in January. I had 3 (out of 40) microinverters fail for several months and they were finally replaced recently. There's also 1 solar panel that has a bad diode and only generates about 2/3 power. Peak energy collected is in the summer at about 1.35 MWh a month for July and August. Annual production is about 12-13 MWh.


    A little data on what a small solar setup can generate... (note that I do have a net meter agreement in place with the power company, but I believe most people can use self-generated energy behind a regular power meter to offset base load home use; check you local rules and regs before attempting to grid tie anything)

    December - 20.1 kWh
    January - 23.8 kWh

    These are from 4 x 150W other panels I had, arranged 2S2P (serial/parallel) running through a 600W rated grid-tied inverter. Got these off Amzn. Power output in winter is up to 300W give or take on a sunny day. The deck's location is in the southeast corner of the house, but gets shading toward mid-afternoon. Also, the sun is very low in the sky all day.

    So the little panels are doing okay IMO. One of the offsets is for the microinverter and panel failures. Another is the myriad phantom loads all over the house with our AC adapters powering the internet of things devices, cell phones, etc.
    Last edited: Feb 7, 2020
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  3. EdwinTheMagnificent

    EdwinTheMagnificent Legend In His Mind

    Thanks , Bill. I am going to study that later.
    BillLin likes this.

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