The idea is for a household that has rooftop or rooftop space to transform from an electricity consumer to a “producer”. In fact, by installing the right batteries (accumulators), the “manufacturer” can also become an energy saver. What does he get as a “producer”? Essentially, the privilege of consuming your own electricity – as long as the demand is calculated correctly – and paying nothing to the supplier, at least for the “competitive” part of the electricity bill. And what can you get if he also puts batteries? This provides, firstly, a reliable source of energy in the event of a power outage and, secondly, the possibility of significantly reducing the so-called “non-competitive payments” on the electricity bill, i.e. payments we pay to DEDDIE, ADMIE, etc.

In the coming weeks, the issue of installing photovoltaics on rooftops or rooftops will be in the spotlight thanks to a subsidy program that the Ministry of the Environment will introduce. About 700 million euros will be allocated to install panels and batteries in at least 250,000 sites, with subsidies that will be received by the “winners” (the process will be completed in order of priority), amounting to 30 to 60% of the cost of photovoltaic. Obviously, those who receive subsidies will further reduce the payback period of investments.

But one year, which is in any case too little for an investment of several thousand euros, since it can be limited to even 7-8 years, depending of course on the consumption of electricity, but also on the sales price of each kilowatt-hour.

How exactly an investment in a photovoltaic plant that produces electricity and balances it with each household’s consumption works can be seen in the following example, which is based on the data prevailing in the market today. Annual household consumption is about 9,000 kilowatt-hours. To cover this consumption, a 7 kilowatt photovoltaic array has been installed (this power is expected to be the maximum allowed in the subsidy program). The investment is approximately 9,000-10,000 euros without batteries. After the investment is completed, the household stops paying for electricity, which, at a price per kilowatt-hour of 0.16 euros, amounts to 1455 euros per year. The household will still only pay about 760 euros per year, which is the so-called non-competitive fee. How many years will it take to pay back the investment of 10,000 euros? Approximately from 6 to 7. And if there is a subsidy of about 50%, then in half a year.

If the household’s annual electricity demand is higher, the payback period is limited, and if consumption is low, it will be longer. A small photovoltaic installation that will produce 3,000 kilowatt-hours per year can pay for itself in 9 years. Conversely, with a consumption of 13,000 kilowatt-hours per year (for example, in a large household with a heat pump), the payback period can be reduced to 6.4 years. How long does photovoltaic “live” for? About 20-25 years old. So after the first 7-8 years – in the worst case – profits begin to be fixed.

What difference would it make to the household if they also installed batteries? Let’s go back to the 9000 kilowatt-hour example. To cover a 7 kW photovoltaic array with batteries, the required investment can even be doubled, reaching 20,000 euros. What will the household get? It will also reduce regulated costs by ensuring that the property is still powered even in the event of a mains failure (batteries will act like a very large UPS). But almost certainly the payback period will increase. A photovoltaic battery with batteries has other features: it helps to ensure the stability of the power supply system, and can also make a household energy independent, even allowing for a complete blackout.

→ And if there is no roof or terrace?

And what will household members do in an apartment building? What happens to real estate where there is not enough space for a roof or tiles? What solution can a tenant offer to reduce the electricity bill? There is also a “virtual photovoltaic” solution on the market. In essence, the consumer pays a lump sum and buys the production capacity of a photovoltaic plant built by the electricity supplier. What does he win? In fact, a discount on the electricity bill, which in today’s conditions is 0.08 euros per kilowatt-hour. For every 1,000 euros of investment, a discount of 116 euros per year is essentially guaranteed, so the return on investment is approximately 11-12%. What are the benefits of this investment? Firstly, there is no stress in maintenance and good performance of photovoltaics. Second, there is “freedom” as the discount can be transferred from one property to another (ideal for tenants). Thirdly, the discount is guaranteed and disconnected from electricity consumption. In conventional photovoltaics, compensation occurs within three years. If during this time more current is generated than will be consumed, the difference is lost. Therefore, virtual investment may seem like a good solution for holiday homes. What can be considered a disadvantage? The return on investment is not “fixed” (it depends on the sale price of electricity on the exchange), and a commitment is required until the end of the contract with a particular supplier.