freedomlives
New Member
Back at the end of winter I bought 12 460Wp panels (50V OCV) from a local seller who'd bought a container from China (which he told me he'd almost sold all of them). My concern was what the war could do in the short term to availability of electric power, and obvious comprehension that it would lead to higher energy prices, due to cutting off natural gas. Thus, I also figured there might be a spike in price of the panels. I'd been toying with the idea of PV for our house for years, but the economics didn't make as much sense before, so only solar power I have been using so far is for charging the electric fence for my goats and sheep.
From looking on this forum, I think I've figured out the battery as well, I didn't realize prismatic cells were so cheap, though I still have some questions before I send the money to Luyan in China: https://diysolarforum.com/threads/entire-diy-lfe-battery-from-luyan.45885/
Where I am now is figuring out which inverter I need. I don't want to do grid-tie, there's really no point, because our monthly consumption is around 500kWh, and looking at the EU solar calculator peak production will be 700kWh in August. In the future, I would consider buying more panels to boost winter output. 8 months of the year it should produce all we'll need to consume:
The devices which need the greatest amount of power is our well pump (3 phase, 2.2kW) and waste water pump (single phase, 2.2kW). This latter runs for about 15 minutes most days. The well can be running for up to a few hours if we're watering the garden. I did buy an inverter drive for the well pump that should allow it to run off of single phase power, though I've not hooked it up. I would be able to make a circuit that would block one pump from starting if the other is running (the wastewater pump pumps out a sump while there's still reserve for more waste water to go into the sump), and that way avoid the situation where the two pumps are pulling 4.4kW of energy and someone in the house plugs in a vacuum cleaner while the washing machine is running.
Otherwise we've got 2 chest freezers, a fridge, as well as one smaller freezer that sometimes gets used, and then normal appliances- washer, dishwasher, dryer (but it is a heat pump model). Then smaller, constant loads: one desktop tower is running all the time, as it records security camera footage and has an MQTT server, during winter there is a pump for radiators, during summer a pump for a frame pool - these are consuming 45W or so continuously (pool pump could run just during day in summer, but radiator pump will run at night too).
Given low production in winter, I am going to wire it so certain loads will be just on grid during that season. I do consider the possibility of charging the battery from the grid at times too. Electricity is 4¢ cheaper from 0:00-6:00 and 13:00-15:00, and that sort of savings probably isn't worth fooling with, but if the tariffs change in the new year, there could be a wider spread.
The price situation of grid electricity for us is 12¢/kWh during low tariff time periods, and 16¢/kWh during the rest of day. The government has announced that consumers will not pay more than 16¢/kWh next year for the first 4000kWh (so our cost of grid consumption during the low light months shouldn't increase), but also they threaten nationalization of electric companies to achieve this goal, and I can imagine the situation here could deteriorate to the point of rolling blackouts or some rationing schemes.
So anyway, I'm very interested in suggestions of AIO inverters, or else separate components that could be applicable to my situation. From what I can tell, a 3phase inverter would need to be pretty big to handle the single phase loads- it would be convenient tho to have 3 phase for the feed grinder and cement mixer, but these could also just be run off the grid, as they aren't critical.
Other criteria is that I don't want to grid tie - grid tie inverters have to be approved by the electric company, and the list of approved hybrid ones for grid tie isn't that exciting. Only the Solax model listed there seems like a good spec, but seems like its out of production. (List is at the bottom of this page after clicking last line of text "Schválené typy hybridných systémov pre inštaláciu v DS VSD, a.s.")
From looking on this forum, I think I've figured out the battery as well, I didn't realize prismatic cells were so cheap, though I still have some questions before I send the money to Luyan in China: https://diysolarforum.com/threads/entire-diy-lfe-battery-from-luyan.45885/
Where I am now is figuring out which inverter I need. I don't want to do grid-tie, there's really no point, because our monthly consumption is around 500kWh, and looking at the EU solar calculator peak production will be 700kWh in August. In the future, I would consider buying more panels to boost winter output. 8 months of the year it should produce all we'll need to consume:
The devices which need the greatest amount of power is our well pump (3 phase, 2.2kW) and waste water pump (single phase, 2.2kW). This latter runs for about 15 minutes most days. The well can be running for up to a few hours if we're watering the garden. I did buy an inverter drive for the well pump that should allow it to run off of single phase power, though I've not hooked it up. I would be able to make a circuit that would block one pump from starting if the other is running (the wastewater pump pumps out a sump while there's still reserve for more waste water to go into the sump), and that way avoid the situation where the two pumps are pulling 4.4kW of energy and someone in the house plugs in a vacuum cleaner while the washing machine is running.
Otherwise we've got 2 chest freezers, a fridge, as well as one smaller freezer that sometimes gets used, and then normal appliances- washer, dishwasher, dryer (but it is a heat pump model). Then smaller, constant loads: one desktop tower is running all the time, as it records security camera footage and has an MQTT server, during winter there is a pump for radiators, during summer a pump for a frame pool - these are consuming 45W or so continuously (pool pump could run just during day in summer, but radiator pump will run at night too).
Given low production in winter, I am going to wire it so certain loads will be just on grid during that season. I do consider the possibility of charging the battery from the grid at times too. Electricity is 4¢ cheaper from 0:00-6:00 and 13:00-15:00, and that sort of savings probably isn't worth fooling with, but if the tariffs change in the new year, there could be a wider spread.
The price situation of grid electricity for us is 12¢/kWh during low tariff time periods, and 16¢/kWh during the rest of day. The government has announced that consumers will not pay more than 16¢/kWh next year for the first 4000kWh (so our cost of grid consumption during the low light months shouldn't increase), but also they threaten nationalization of electric companies to achieve this goal, and I can imagine the situation here could deteriorate to the point of rolling blackouts or some rationing schemes.
So anyway, I'm very interested in suggestions of AIO inverters, or else separate components that could be applicable to my situation. From what I can tell, a 3phase inverter would need to be pretty big to handle the single phase loads- it would be convenient tho to have 3 phase for the feed grinder and cement mixer, but these could also just be run off the grid, as they aren't critical.
Other criteria is that I don't want to grid tie - grid tie inverters have to be approved by the electric company, and the list of approved hybrid ones for grid tie isn't that exciting. Only the Solax model listed there seems like a good spec, but seems like its out of production. (List is at the bottom of this page after clicking last line of text "Schválené typy hybridných systémov pre inštaláciu v DS VSD, a.s.")
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