Post AtA0srvbCytvdI6WB6 by icanbob@techhub.social
(DIR) More posts by icanbob@techhub.social
(DIR) Post #AtA0slINrry33vi7Dk by icanbob@techhub.social
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For 45 years I’ve been hearing that renewables particularly solarPV are the future of energy grids. Costs of the PV collector portion of such a system have declined substantially over that time.I’m a big believer in real live data over theoretical models. I am now in a position to create my own little experimental dataset. I live in Ontario on a rural property.#solarPV
(DIR) Post #AtA0so03oS5pRyA1Zo by icanbob@techhub.social
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My home is entirely electrified; ground sourced heat pump, well water, all electric appliances. My grid connected power meter collects data on kWh usage hourly. I have friend 5 km away in a similar rural setting that has 16kW solarPV installed. His data shows 1000kWh/yr/kW which is enough to supply my home annually. By combining the two hourly kWh datasets I can answer the question “how much seasonal storage would be required to run my home on PV power?”
(DIR) Post #AtA0sqJHDyeWc9AOo4 by icanbob@techhub.social
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Results so far. Dataset started 2023Nov01. To bring my home through those 6 weeks we would need 600kWh of seasonal storage in the vault on Nov1. During those 6 weeks there have been 5 days where there hasn’t been a single hour with a PV surplus to send to storage.Stay tuned for more results into the spring.
(DIR) Post #AtA0srvbCytvdI6WB6 by icanbob@techhub.social
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I have brought my dataset up to 2023Dec15. It has been a warm winter without much sun in my part of Ontario so far in Dec. To bring my home through from Nov1 we would require 950kWh in storage in vault on Nov1. Interestingly Dec 15 was a very warm (12C) and sunny day. Despite this, the 16kW PV output could not entirely match home GSHP load that day even with the significant passive solar heating from my southern window exposure./4
(DIR) Post #AtA0stJk2ho5wSPJRo by icanbob@techhub.social
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I’ve brought my dataset up to 2023Dec25. The past 10 days have been horrible for PV production. All the while outside temps, while warm for these parts, have hovered around 5C during day. My GSHP still needs to consume power to heat my home. To bring my home through from Nov1 now requires 1400kWh of seasonal storage to be in place Nov1. There now have been 13 days with no surplus PV at any point in the day. 1400kWh=$1400000 in Tesla Powerwalls./5
(DIR) Post #AtA0supKQkfSciC3Jw by icanbob@techhub.social
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I’ve brought dataset up to 2024Jan4. PV production continues to be horrible in my part of Ontario. To bring my GSHP heated home from 2023Nov1 now requires 1900kWh of storage be in the vault on Nov1. There have now been 21 days since Nov1 with no surplus PV at any point in the day. Jan 4 was actually a very sunny day but since my neighbour’s PV panels are covered by a thin layer of snow and the outside temp maxed at -5C, Jan 4 was one of the 21 days with no surplus./6
(DIR) Post #AtA0sw9vTejoksq144 by icanbob@techhub.social
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Dataset is up to 2024Jan15. PV production continues to be horrible due to lack of sun and snow/ice cover on panels. The weather has turned colder (-10C daytime high). This has boosted my GSHP load substantially. The combination now means that I would need 2.6MWh of seasonal storage in the vault on Nov1. There have now been 32 days with no PV surplus at any point in the day. At Tesla Powerwall prices this storage would cost $2.6M for my one home./7
(DIR) Post #AtA0sxJtA6IkM4VUES by icanbob@techhub.social
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Dataset is now up to 2024Jan27. PV production continues to struggle but cold weather has moderated. We now need 3.5MWh of seasonal storage in vault on Nov1 to get my home through. There have been 42 days with zero PV surplus at any point in day. 3.5MWh=150kgH2 run back through fuel cell=269Tesla Powerwalls=51olympic swimming pools of water pumped to height of my roof./8
(DIR) Post #AtA0syuRFh8FHicBqC by icanbob@techhub.social
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Dataset is up to 2024Feb3. Feb3 was the first day since early Nov that the PV output exceeded my GSHP load over 24 hrs. Ie. More was added to storage than taken out. We now need 3.7MWh of seasonal storage and there have been 45 days with zero PV surplus at any point in day. 3.7MWh=160kgH2=285 Tesla Powerwalls=54 Olympic pools of water up 10m. We may have turned the seasonal corner because days are getting longer (=more PV on sunny days) and weather is warming (=less GSHP)./9
(DIR) Post #AtA0sywZ7mpjOJbt9k by icanbob@techhub.social
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What if my GSHP was powered by an in home fuel cell. My house uses ~70kWh/day to drive my heat pump. Assuming COP of 3 my house needs ~210kWh/day of 20C heated air. A fuel cell is about 60% efficient. The 40% is rejected as heat above 20C. So fuel cell produces 0.67kWh heat per kWh electric. Daily heat = ( kWh e * 3) + (kWh e * 0.67)=kWh e * 3.67KWh e (fuel cell) = 210/3.67 = 57kWh with in home fuel cell vs 70 kWh or 82% of electrons from fuel cell for same GSHP heat.