nordanney
2024-05-12 15:14:14
- #1
Do you need to take out financing for the photovoltaic system (the title still says PC – maybe a few IT geeks will join in) or are you paying cash? You can quite easily calculate whether and how the system pays off. Currently, prices for a 10kWp system are around 1,200-1,300€ per kWp all in (please don’t complain, these are current average prices across the country – you can also find them compiled fairly well – if you look, you will find). So, about €12,000 investment. With this, you will currently cover about 20-25% of your own electricity demand – assuming an external electricity price of 33 cents, you save about 25 cents/kWh, so about €150 per year (estimated 600 kWh). Besides that, you will roughly feed in 9,400 kWh of electricity at 8.1 cents/kWh, so about €760 p.a. Together that is €910 per year – with a €12,000-13,000 investment, the system pays off after 13-14 years. Not so sexy, because you could also invest your money elsewhere in parallel. But now the variables come into play: - annual electricity price increase - heat pump - e-car Depending on how you calculate, the amortization will improve dramatically. For example, I have a self-consumption of 25%, so 2,400-2,600 kWh per year (heat pump and car). That already looks significantly better. And if the electricity price in 10 years is, for example, 50 cents/kWh, everyone who installed a photovoltaic system on their house today will be rolling with laughter. But what can happen? - performance losses over time, mitigated by performance guarantees of partially over 85% after 20 years - defects on the inverter, mitigated by sometimes very long warranty periods, but after 10 years the warranty/guarantee usually ends The "problem" with small systems like the one you named in your initial post are the anyhow-costs. The scaffolding and standstill time don’t care whether you slap 2kWp or 50kWp on the roof. And the installation or connection doesn’t take that much longer. Only with a small system are they proportionally very high per kWp. Finally, on the topic of storage. Here you have to calculate how expensive the stored electricity becomes or how much you consume from it. Currently, it looks like electricity from the storage is often even more expensive than if you get it from the grid. Therefore, I basically don’t calculate a storage anymore.How big should the system be? Is there an estimate? We consume about 2700 kwh/a.