• Have you tried out dark mode?! Scroll to the bottom of any page to find a sun or moon icon to turn dark mode on or off!

diy solar

diy solar

Purchasing a new house, want to diy solar install.

Yeah, over time I would add more batteries and panels as needed to help with winter months.
Not sure where in US you are, but from the comments SW likely (?) So lots of sun, but also lots of A/C needed. (at least these are at the same time of day generally!)
You should always plan a system from the loads, back to the solar, not the other way around.
The batteries are by far the most expensive part of a solar PV system, so knowing the overnight energy needs is also very important - even if you start with less battery and add over time, plan out the system for the eventual battery needed. (most of us do this, batteries are expensive).
OR work with the utility to have a system where you feed in energy during sunny periods, and draw off energy as you need it. Requires a utility and rates that allow this to work.
Generally, 100kWh/Day / 5 hrs of good solar = 25kW PV array
Two or three days of automy = 200 -300kWh of battery (this is kinda crazy huge, unless you are @timselectric)
- if the weather was poor for solar, does the daily energy load remain 100kWh? ie say it is overcast and rain for two days, what is the power requirement for those two days? often the days with poor sun = days with less A/C it would be best to know what this difference is for planning.
To size the inverters you really need to know two things: Peak load in kW (ie start up loads) and daily energy use in kWh.
If you go with AIO inverters you need to size the SCC part to suit the 25kW array. ie high voltage MPP inputs are best. The EG18kpv is an interesting model I would consider. Keep in mind the "18k" refers to the PV input, not the AC output.
Budget: building a 100kWh/day system with three days of autonomy (300kWh) ground mount 25kW PV is a big project. Breaking it up into parts, done over a period of time can be one way to build it without financing.
 
Sort and sweet.
1. Size your inverter to cover your maximum load, at any given moment.
2. Size your battery to cover your loads, when the sun isn't shining.
3. Size your solar to cover your loads when the sun is shining, and recharge your battery.
 
Not sure where in US you are, but from the comments SW likely (?) So lots of sun, but also lots of A/C needed. (at least these are at the same time of day generally!)
You should always plan a system from the loads, back to the solar, not the other way around.
The batteries are by far the most expensive part of a solar PV system, so knowing the overnight energy needs is also very important - even if you start with less battery and add over time, plan out the system for the eventual battery needed. (most of us do this, batteries are expensive).
OR work with the utility to have a system where you feed in energy during sunny periods, and draw off energy as you need it. Requires a utility and rates that allow this to work.
Generally, 100kWh/Day / 5 hrs of good solar = 25kW PV array
Two or three days of automy = 200 -300kWh of battery (this is kinda crazy huge, unless you are @timselectric)
- if the weather was poor for solar, does the daily energy load remain 100kWh? ie say it is overcast and rain for two days, what is the power requirement for those two days? often the days with poor sun = days with less A/C it would be best to know what this difference is for planning.
To size the inverters you really need to know two things: Peak load in kW (ie start up loads) and daily energy use in kWh.
If you go with AIO inverters you need to size the SCC part to suit the 25kW array. ie high voltage MPP inputs are best. The EG18kpv is an interesting model I would consider. Keep in mind the "18k" refers to the PV input, not the AC output.
Budget: building a 100kWh/day system with three days of autonomy (300kWh) ground mount 25kW PV is a big project. Breaking it up into parts, done over a period of time can be one way to build it without financing.
I am located in Michigan. My power usage may drop a little bit once we move to the new house though, as my current home has a 3 ton central air unit and a 2 ton mini split for my shop area plus equipment I run consumes about 1000 watts around the clock in the shop plus all the other random electronics/computers etc in the house. I have electric monitor that connects to my wifi in my panel in the house and at peak in the summer I am consuming about 7-8k watts when the 3 ton ac is running. When it is off it sits around 4-5k watts. In the winter the 3 ton never runs, but the shop mini split does run all year around just not as often.

The new house does not have central air at all but we plan to add a couple small mini splits to the house and shop area (2-3 12k btu units maybe). The dryer/stove/furnace and hot water heater are on propane at the new house. We would like to switch some of that to electric though as the solar system grows and can run it. I will also be running a welder from time to time in the shop. I think the ek4 18k inverter will be sufficient for our needs and I am going to look into diy batteries as well.

I think to start I would do 9-12k in panels, the ek4 18k inverter and some diy batteries and still have the utility company for when the batteries die. Over time I will add more batteries and panels. I also have a whole house generator that could be implemented as well if utility company power goes down. What other hardware would be needed? Some sort of surge protection would be good for the equipment, will build a shed to house the equipment, there is a concrete pad already in a perfect spot where a shed once was.
 
New house, okay so lots to find out on the load side after you move in. Lots of loads that could be propane or change to elect.
Sorry I forgot your MI location, so winter low light conditions, A/C only for part of the year/summer, you have some known loads, and some you will add.
You mention selling to grid, or not, this may be a decision you have yet to make at this point I suspect, that is until you know more about the (new) utility co, terms, rates, regualtions costs.

I plugged Lancing MI into PVWatts and 10kW array:
30-degrees tilt for late spring summer early fall, 60 degrees for winter: result was 320kwh better production for the five worst months, but snow clearing is the main reason really (for me at least).
Tilting up to 60-degrees will add 75-100kWh of production (per month) in Nov-Dec-Jan which is significant when the whole month is only 600kWh(december) at 30-degrees.
The other option is leave the PV at the steeper angle all the time, not tilting, since the summer will still outproduce the winter even with not ideal angle.
{ie using only 60-degrees all year around according to PVWatts January production per 10kW PV = 766kWh, and July =1104kWh meaning that production is close to steady all year. Although if you know you will need A/C in summer, tilting may be best, 30-degrees July = 1483kWh}
All this will also depend on shading (trees/buildings) and if the PV will be true due South or other angle.
 
Last edited:
New house, okay so lots to find out on the load side after you move in. Lots of loads that could be propane or change to elect.
Sorry I forgot your MI location, so winter low light conditions, A/C only for part of the year/summer, you have some known loads, and some you will add.
You mention selling to grid, or not, this may be a decision you have yet to make at this point I suspect, that is until you know more about the (new) utility co, terms, rates, regualtions costs.

I plugged Lancing MI into PVWatts and 10kW array:
30-degrees tilt for late spring summer early fall, 60 degrees for winter: result was 320kwh better production for the five worst months, but snow clearing is the main reason really (for me at least).
Tilting up to 60-degrees will add 75-100kWh of production (per month) in Nov-Dec-Jan which is significant when the whole month is only 600kWh(december) at 30-degrees.
The other option is leave the PV at the steeper angle all the time, not tilting, since the summer will still outproduce the winter even with not ideal angle.
{ie using only 60-degrees all year around according to PVWatts January production per 10kW PV = 766kWh, and July =1104kWh meaning that production is close to steady all year. Although if you know you will need A/C in summer, tilting may be best, 30-degrees July = 1483kWh}
All this will also depend on shading (trees/buildings) and if the PV will be true due South or other angle.
I have already decided to not sell back, I just want to have panels, some batteries (that I can expand as time goes on and I can afford) and tied to the utility when there is no sun and the batteries are dead, which will be all auto switched I am assuming with the ek4 18k (without power loss?). I am going to buy or probably build a ground mount that I can manually change the angle for winter/summer months.

I suspect the overall power use will be a little less at the new house but even it is the same I think the ek4 18k will provide sufficient power and if for some reason (which I can't imagine) I need more I can add on/upgrade later.

For the system I plan to build is there a list of the kind of devices I would need? My understanding so far would be:

ground mount
solar panels
combiner box (?)
cabling
shed to house equipment
surge protection
some disconnects
distribution busbars
ek4 18k
batteries
electrical panel

I know I have lots to learn but trying to picture how the system should look, what devices are needed and what each thing does etc.

Thank again!
 

diy solar

diy solar
Back
Top