Here are a few. A good rule of thumb for calculating how much energy you will get from a solar panel is to take the solar panel wattage and multiply by 2 in the winter, or 5 in the summer (adjusted a bit according to local conditions). So, for example, a 100W panel will produce roughly 200Wh/day (watt-hours per day) in the winter, and roughly 500Wh/day in the summer. 2000W worth of solar panels will produce 4 kWh/day (kilowatt-hours per day, aka 4000 Wh/day) in the winter and roughly 10kWh/day in the summer. Power and energy are two distinct things. A toaster that uses 1000W (watts) while running, but only runs 10 minutes a day uses 1000 * 1/6 = 167 Wh/day (watt-hours/day). Watts is power, watt-hours is energy. Two different things. For that matter, "amp-hours" is not energy, its just amp-hours. You have to multiply by the voltage to get energy. A 100Ah 12.8V battery is 2560 watt-hours of energy storage. A 25Ah 51.2V battery is ALSO 2560 watt-hours of energy storage. Another one is... 99% of people under-estimate how big a system they need. With that in mind, starting small is a great way to go... cheaper, particularly as a learning mechanism. Start small, but design the system with expansion in mind even if you don't think you'll ever expand it. Because you will. Guaranteed. Make sure you have room for and cable the system such that you can add more batteries in parallel, that you can add more solar panels, more charge controllers, more or bigger inverters. And so forth. -- Don't be scared of using higher battery voltages. 12.8V is old-school. It is either very limiting or one winds up using ridiculously thick cables and large, expensive charge controllers and so forth trying to expand it later on. Think about using 25.6V or 51.2V (colloquially "24V" and "48V") from the start. A quick reference: 12.8V: When you have tons of legacy 12V gear. Thicker cables, difficult to expand, you have to deal with a lot more amps. But you avoid having to put together a DC-DC or down-buffer battery to run the legacy 12V gear. Think carefully, the decision is not as straight-forward as it might seem. An old lead-head used to dealing with the bulkiness can stick with 12V gear and still be happy. But most other people will quickly hit a wall. 25.6V: Easy way to go for "small" new systems without too much worry. 2500W+ of continuous power with only 2 AWG cabling. Easy fusing, few worries about ARC shorts, etc. 51.2V: Best way to go even for small systems but requires more knowledge on fusing and solar panel topologies to meet the stricter requirements of a higher voltage system. 5000W+ of continuous power with only 2 AWG cabling. -Matt
Alot of people will tell you to have at least 200w of solar per 100ah of battery. Im living in mid Michigan and i run about 400w of solar per 100ah of battery. We can get upwards of 7 days of no sun in the winter. So having the extra panels comes in handy. In the summer time we have plenty of sun to run fridges and freezers, internet, fans ect. Where you live can play a crucial role in how much solar you can produce as well. And this all started because we wanted power when we go camping, and well, the system grew.
Good things to keep in mind.
Here are a few.
A good rule of thumb for calculating how much energy you will get from a solar panel is to take the solar panel wattage and multiply by 2 in the winter, or 5 in the summer (adjusted a bit according to local conditions). So, for example, a 100W panel will produce roughly 200Wh/day (watt-hours per day) in the winter, and roughly 500Wh/day in the summer. 2000W worth of solar panels will produce 4 kWh/day (kilowatt-hours per day, aka 4000 Wh/day) in the winter and roughly 10kWh/day in the summer.
Power and energy are two distinct things. A toaster that uses 1000W (watts) while running, but only runs 10 minutes a day uses 1000 * 1/6 = 167 Wh/day (watt-hours/day). Watts is power, watt-hours is energy. Two different things. For that matter, "amp-hours" is not energy, its just amp-hours. You have to multiply by the voltage to get energy. A 100Ah 12.8V battery is 2560 watt-hours of energy storage. A 25Ah 51.2V battery is ALSO 2560 watt-hours of energy storage.
Another one is... 99% of people under-estimate how big a system they need. With that in mind, starting small is a great way to go... cheaper, particularly as a learning mechanism. Start small, but design the system with expansion in mind even if you don't think you'll ever expand it. Because you will. Guaranteed. Make sure you have room for and cable the system such that you can add more batteries in parallel, that you can add more solar panels, more charge controllers, more or bigger inverters. And so forth.
--
Don't be scared of using higher battery voltages. 12.8V is old-school. It is either very limiting or one winds up using ridiculously thick cables and large, expensive charge controllers and so forth trying to expand it later on. Think about using 25.6V or 51.2V (colloquially "24V" and "48V") from the start. A quick reference:
12.8V: When you have tons of legacy 12V gear. Thicker cables, difficult to expand, you have to deal with a lot more amps. But you avoid having to put together a DC-DC or down-buffer battery to run the legacy 12V gear. Think carefully, the decision is not as straight-forward as it might seem. An old lead-head used to dealing with the bulkiness can stick with 12V gear and still be happy. But most other people will quickly hit a wall.
25.6V: Easy way to go for "small" new systems without too much worry. 2500W+ of continuous power with only 2 AWG cabling. Easy fusing, few worries about ARC shorts, etc.
51.2V: Best way to go even for small systems but requires more knowledge on fusing and solar panel topologies to meet the stricter requirements of a higher voltage system. 5000W+ of continuous power with only 2 AWG cabling.
-Matt
Thanks for adding to the conversation.
@@OurBlackCatCottage everytime I look (suburbia) at any solar it is NOT cost effective. But I can see it being viable off grid.
Alot of people will tell you to have at least 200w of solar per 100ah of battery. Im living in mid Michigan and i run about 400w of solar per 100ah of battery. We can get upwards of 7 days of no sun in the winter. So having the extra panels comes in handy. In the summer time we have plenty of sun to run fridges and freezers, internet, fans ect. Where you live can play a crucial role in how much solar you can produce as well. And this all started because we wanted power when we go camping, and well, the system grew.
I started because I saw a solar light at a Dollar store. Now I have more solar stuff than I can count. LOL
Also consider using less electricity.
Always a consideration for sure.
And if you have you’re panels behind window glass you automatically LOOSE 50% sunlight going through clear glass you loose 50 %
First step: open your wallet. Is it empty, stop and go get a 6 figure job
interesting perspective. LOL.