I went into solar in the house almost four years ago, when electricity prices started strongly raising. Back then, batteries were quite expensive and most companies were offering you to pay for your exceeding power calling that service a "virtual battery" as you could deduct that from your invoice. As I live in a quite sunny country and all our solar panels face south, we could soon feel a nice reduction on the monthly costs.
Most city houses in Spain have electricity for all appliances and gas for cooking, house and water heating. So you end up having two invoices for energy and paying the monthly base costs no matter if you consume or not.
As years go by, price of electricity keeps going up and price of batteries, panels and inverters going down. And at the same time, the price companies pay you for the exceeding energy you give them keeps going down as there is more and more energy produced at the same hours of the day. The conclusion is that if you do not have a battery, the electricity you generate during the day is paid at almost zero, but at night, the one you consume cause you do not generate anymore is expensive.
Also, old inverters are not hybrid, meaning they need to be connected to the main network, so if there is a blackout, even when the sun is shining, your system stops working and you run out of power.
After experiencing the freedom of being off grid in the farm, I decided to make a new investment in the house, change the inverter for a hybrid one and add batteries. The panels are 400watts, so although there are more powerful ones in the market, I still can keep those, although I have increased the capacity of the inverter in case I decide to change the panels in the future.
We have 10 400watt pannels, our inverter is a 5kw one and the new one we are getting is 6kw. There is no more roof room facing south, so the only way to increase production is adding some panels facing north or changing the ones we have for more productive ones.
We are adding 2 8kw batteries to have a total of 16kw. That shoud be enough to let us charge the house night consumption and recharge the batteries again during the day. We have only 5kw batteries in the farm and have had no problem at all during the summer, although the consumption there is way lower and I still have to see how the system behaves this winter when I spend a few days there. The new system allows us to add 4 more batteries in a quick and easy plug and play, so if needed we can easily increase that value.
My final goal is to eventually go off grid, keep a gasoline generator as a backup and learn to save energy when not needed as I do in the farm. So far, I plan to get rid of gas in the house, changing the cooking stove and the water heater. We may need to add an extra AC in the sleeping room to use it also as heater in the winter but we live in a warm area so temperatures rarely go below 10ºC here anytime in the winter. Getting rid of gas also keeps our base gas cost to zero which adds to the savings.
All in all is a big investment, and with today's energy prices they payback is 7 years, but getting rid of gas costs will reduce that time to probably 4, and I am sure electric power prices will keep raising in the coming months/years.
I would probably wait if I would only consider economic savings, but having a grid-free system if needed and eventually go off grid is something I want to invest for to gain resilience and to avoid any added costs to the electricity bill, as there are many added costs there you cannot avoid. I will post my experiences once the system is installed and a few weeks after, once I start 'feeling' the consumption and cost results.