Solar panels, is it possible to reduce bills to £0 with them?

HappyMJ

Ben84 wrote: »

Sorry, I can't answer your question. However, I'm very curious how you're managing to use just 6 kWh a day for all your household energy needs?

1kWh per day excluding heating. Maybe they don't use much stuff. Hot water may be heated by gas or another fuel. My base summer usage is quite low at 2kWh per day and that can be cut further if I really wanted to.

Ben84

HappyMJ wrote: »

1kWh per day excluding heating. Maybe they don't use much stuff. Hot water may be heated by gas or another fuel. My base summer usage is quite low at 2kWh per day and that can be cut further if I really wanted to.

I don't know, my fridge alone (not a large model or anything) uses one kWh a day on average. I think there would have to be a bit more than everyday frugality to this?

HappyMJ

Ben84 wrote: »

I don't know, my fridge alone (not a large model or anything) uses one kWh a day on average. I think there would have to be a bit more than everyday frugality to this?

Turn the fridge off. What's a fridge for anyway? Just for keeping stuff cold. What about using tinned food? Cooking up what's needed and eating it all straight away. I've turned the fridge off...no need for it. Rice and pasta are both dried. Sauces come in jars. Meats are tinned or cooked and eaten on day of purchase. I rarely drink milk when I do it can be left on the side in winter as it's so cold it'll last quite a few days after opening. Spreads are OK left out of the fridge. When I do use the fridge it uses less than 0.3kWh per day. It's rated at 113kWh per year.

Ben84

HappyMJ wrote: »

Turn the fridge off. What's a fridge for anyway? Just for keeping stuff cold. What about using tinned food? Cooking up what's needed and eating it all straight away. I've turned the fridge off...no need for it. Rice and pasta are both dried. Sauces come in jars. Meats are tinned or cooked and eaten on day of purchase. I rarely drink milk when I do it can be left on the side in winter as it's so cold it'll last quite a few days after opening. Spreads are OK left out of the fridge. When I do use the fridge it uses less than 0.3kWh per day. It's rated at 113kWh per year.

My fridge is old and I'm sure less efficient than a new one, but the main point I wanted to make is that a single kWh a day doesn't go far in a modern household. Just one common appliance can use that.

As for the fridge itself, I like it and find the convenience it gives me for ~1 kWh a day good value. However, if I did decide to stop using it for environmental reasons, I'm not convinced it would pay off. Food is very energy intensive to produce, I doubt I'd have to waste that much more from it going bad to put a significant dent in the energy savings, or even to make them negative. However, even if I did manage to avoid any extra food waste, relying on metal and glass packaging more is not a low energy or low resource option either. Digging up all that iron ore, transporting it, smelting it, forming metal, or the sand to make glass and melting it. I don't have exact numbers, but it looks like I'd be swapping one energy and resource consuming habit for another - one that's possibly even more energy and resource intensive than running a fridge?

Energetic_2

berbastrike wrote: »

If I am living alone and want to get solar panels installed, is it possible that the power generated by them is enough to run the whole houses electricity and heat meaning £0 bills for the rest of my life?


average electricity uses - 1kW per day
also using electric heaters instead of gas - 5kW per day

total of 6kw would be needed per day.

There are some devices on the market such as the Nedap Powerrouter that have the capability for modular battery packs to be added to the system. Rather than exporting during the day the batteries will charge giving you the use of them at night, upon reaching their optimum discharge level you will switch back to the grid.

These will get you pretty close to no electricity bills with your levels of consumption without the need for riduculous auxillary battery banks to cover 5 days of autonomy, best of both worlds.

They are a bit more expensive than a normal inverter and will also allow you to use your generated power during a grid outage unlike any other invterter.

PM me if you want.

zeupater

Energetic wrote: »

There are some devices on the market such as the Nedap Powerrouter that have the capability for modular battery packs to be added to the system. Rather than exporting during the day the batteries will charge giving you the use of them at night, upon reaching their optimum discharge level you will switch back to the grid.

These will get you pretty close to no electricity bills with your levels of consumption without the need for riduculous auxillary battery banks to cover 5 days of autonomy, best of both worlds.

They are a bit more expensive than a normal inverter and will also allow you to use your generated power during a grid outage unlike any other invterter.

PM me if you want.

Hi

What's the full cycle efficiency for these units & do you consider them to be cost viable against importing at an averaged import cost of (say)15p when taking battery replacement, financing etc into account ?

Z

spgsc531

I'm sure this will become more common and viable in time.

I'm sure I read somewhere that one of the major inverter manufacturers was bringing out an inverter with battery pack, can't remember which at the moment.

Energetic_2

zeupater wrote: »

Hi

What's the full cycle efficiency for these units & do you consider them to be cost viable against importing at an averaged import cost of (say)15p when taking battery replacement, financing etc into account ?

Z

Tbh I don't think they're viable financially really unless you have a very unreliable grid but some people are more interested ideologically in not paying utility bills. We've had customers concerned about solar storms and passing comets knocking out the grid also.

Not installed any yet but great concept the additional cost always makes it difficult to justify but with continued lack of investment in the grid we may see more interest in the coming years.

grahamc2003

Energetic wrote: »

There are some devices on the market such as the Nedap Powerrouter that have the capability for modular battery packs to be added to the system. Rather than exporting during the day the batteries will charge giving you the use of them at night, upon reaching their optimum discharge level you will switch back to the grid.

These will get you pretty close to no electricity bills with your levels of consumption without the need for riduculous auxillary battery banks to cover 5 days of autonomy, best of both worlds.

They are a bit more expensive than a normal inverter and will also allow you to use your generated power during a grid outage unlike any other invterter.

PM me if you want.

Would you mind posting a link to this storage system?

Storing 5 days worth of energy certainly won't be cheap and is generally viewed as non-viable at all for the average person. While solar generation at this time of the year is unlikely to be zero, it's likely to be very low - last week I generated 2kwh. At the same time, heating would be well above average heating needs, so swings and roundabouts there.

The op, I think, is saying he uses 6kWh per day, which is incredibly low if it includes electric heating, but anyhow, lets run with those numbers.

Let's assume a low cost low tech system, and just consider the battery costs with rough estimates. To get 30kWh (5 days, assuming full charge and full depletion - in itself problematic) he'd need to generate 60kWh assuming about 75% charging efficiency, to store 45kWh, and have available 30kWh (assuming about 75% discharging efficiency).

So about 45 average sized car batteries would be required, roughly, to store 45kWh (1kWh per battery). Reasonable quality batteries would be £100 give or take, so £4,500 for the batteries. There are other problems and other costs of course.

Would be interesting to see how the system you are describing compares with the low tech ball park costs.

Energetic_2

spgsc531 wrote: »

I'm sure this will become more common and viable in time.

I'm sure I read somewhere that one of the major inverter manufacturers was bringing out an inverter with battery pack, can't remember which at the moment.

SMA do a battery UPS, Sunny Backup, it is essentially an automatic system rather than a 'lifestyle choice'. They also do the sunny island which is a synthetic grid and isolator to keep the inverter going on an outage without sending anything down the line.

Power one do off grid and island systems also, there are probably more but it's been a while since I looked into it in any detail.

E