A typical residential home may see a proposed solar electric system sized between a 5 – 10kW system. It all depends on how much energy you use AND what kind of ‘true-up’ policy your utility has. It is very important to consider this policy when sizing your PV system. A PV system or Photovoltaic System will offset the kWh’s on your utility bill. It will NOT offset your fixed monthly fee typically, only the kWh rate your utility is charging you, typically between 9 and 14 cents. If your system over produces in any given month or year you will be paid back at a wholesale value or if your lucky something in between wholesale and retail. In the state of WI, there are very few utilities that will give you retail value for excess solar energy produced within the ‘true-up’ period.
All old collectors were removed from the roof and there is a new design using them for space heating in a Geothermal ‘Pump & Dump’ system.
Utility approvals, permitting and state inspections are now a norm for the state of WI. It is essential and a money saver to get these logistics taken care of before any part of the installation takes place. Utility approvals are easy if you understand their wants. Adding batteries to the mix is complicating things, especially because the utilities don’t understand all the technologies and how they work. The industry is coming up with some fun things. Grid-tied, off-grid, hybrid inverters with three way switches so you can be off-grid at any time of your choosing, or using battery storage when prices are higher. Fun, but wiring and programming of these systems can be complex and should be done by a license master electrician. Also, working with manufacturers of this equipment is essential during the design phase.
Below is the electrical for the system. Two 12kW Sol-Ark Inverters and 20kWh of capacity.
What about Do-It-Yourself systems??? We support those trying to go solar at lower costs if that means they can do it. You should always have a master electrician do the interconnection of the system. Most utilities will require that license number in order to commission the system anyways. Structural consideration are good to get from a professional or racking company as well. Design needs to be efficient. A good solar window and understanding the electrical calculations of PV system design is important. If you spend $10,000 on a system, you still want the system to function to the best of it’s ability, don’t you? Plus, your system will most likely need to pass a state inspection now. Do you know your local AHJ?
Here at Northwoods Sustainable Solar we want everyone who wants to live more sustainable lives to be able to achieve that within their budget. If it is just information you need, call or contact in any way you see fit.