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points by LeonM 3 days ago | 0 comments
I found most people fixate on the price of the cells/panels, but forget that the rest of the installation required to use said panels easily exceeds the price of the panels by a factor of 3~4. Think mounting hardware, cabling, inverters, batteries, control hardware, labour, etc. It all adds up.

I've been pricing a PV system recently, and I was surprised at how low the price of panels already is. In most estimates I received the panels itself were less than 20% of the total installation costs. Granted, I am looking at a 3-phase system with plenty of battery capacity. For a more typical household setup with 1-phase and moderate battery capacity that percentage will shift a bit.

In my case the quotes are roughly: 40x430Wp panels (~€4000), 3x (3-phase) inverter/chargers (~€5000), batteries (~€5000), auxiliaries (~€1500), cabling (~€2000), mounting hardware (~€2500), labor (~€5000), planning/permissions (~€1000). So total project price is ~25k, of which the panels are only ~€4000. And that doesn't even count the construction of a utility building to house the batteries and inverters, the EV chargers, etc.

On a side note: I found that battery prices have also dropped significantly already. If you're willing to do some assembly yourself you can get ~15kWh of LiFePO4 for just over €1k.

Also, for those wondering: for my situation the ROI of this setup is expected to be about 5 years. This will be quicker if I get an EV, which I am planning on.

[–] sandworm101 2 days ago
Micro plug-in panels address the pricing issues. If every panel has a built-in inverter/controller then everything can be wired at the factory, radically reducing costs. As they are all pushing AC then they can all be plugged in to household outlets without electricians getting involved. Mounting remains an issue but as purchase costs come down the need for a perfect mounting system diminishes.
[–] TedDoesntTalk 2 days ago
ROI on 25000 EUR in 5 years?? How are you spending 5000+ EUR per year on electricity?
[–] LeonM 1 day ago
> How are you spending 5000+ EUR per year on electricity?

Energy prices are high in my country, and price spikes have become more frequent.

My house is currently heated by natural gas, which costs about €200/month avg plus another €550/year in standing charges. Prices for natural gas is expected to rise. By switching to heat pumps and induction cooktop I can disconnect from the gas distribution grid completely. This will safe about €3k in gas costs annually (against current rates) but obviously increase my electricity usage significantly. So in my country €5k/year in electricity isn't as ridiculous as it sounds.

I'm projecting my electricity consumption to be ~€3.5k a year once I have fully switched to electric heating, so this is where generating my own electricity starts to make sense.

The PV array I'm planning is very much over dimensioned for my use. To make financial sense my PV installation must produce more than I consume over the year. Not only will my electricity bill be effectively €0, I will also be able sell overproduction back to the grid during summer. By using variable rate discharging I can optimize the return. I am projecting that selling overproduction will net about €1k annually.

The rest comes from from dynamic energy tariff trading. The battery will be used as a grid stabiliser, so it'll charge (from the grid) when electricity is cheap/negative and discharge back to the grid when return rate is high. This is projected to net another €500~€1000 annually.

If I add an EV I'll safe about 3k/year in fuel, though my electricity use will obviously go up, I won't have as much overproduction anymore.

In my country PV only really makes sense when it's combined with batteries and connected to the grid with a variable rate contract. The more battery capacity you have the more value/income it can create stabilising the grid. So really the price per kWh of battery capacity is the driving force in the ROI of a PV setup.