Add on's for solar panels

Cocksure

I've seen loads of threads on here for electric solar panels, but none that mention the add on's you can get to max your usage from them. I was just wondering if people on the whole didn't bother or weren't aware of them?

Surely i cant be the only person who heats his water this way and/or has battery storage?

neilball

There are plenty of people using an Immersun or similar to reduce/remove their export of excess PV generation but I've not come across to many people using battery storage due to costs. Most of the people I know with batteries are aiming to be fully off-grid and are using a variety of generation sources to feed the battery bank and a variety of controls to try and minimise the chances of damaging batteries. These off-grid systems are using expensive lead-acid batteries so need a fair amount of space and load-bearing due to the excessive weight. However these kinds of setups require a fair bit of management so are for committed individuls! They are not fit-and-forget like the units promised by Tesla and some of the other companies offering Li-ion batteries.

I don't bother with Immersun as I have a packaged ground source heat pump with integrated hot water cylinder which is not easy to modify. Not do I currently bother with battery storage as I don't export enough to make it worthwhile.

Cocksure

It's expensive at first that's for sure but as you said the ultimate aim is to be off grid. Still the savings on the electoral bill is very noticeable

What type of ground source heating have you got? Reason I ask is because I have heard mix results with them.

neilball

I use a Nibe heat pump which runs my hot water and wet underfloor heating. I also have 750m of external plain pipe in trenches that are in excess of 1m deep (no slinkies used in my installation). Heat pumps are a tried and tested technology that works very well when properly designed and appropriately utilised. Unfortunately there are a lot of less-than-scrupulous companies charging high costs for heat pumps to replace boilers in inappropriate heating systems that have to operate with high flow temperatures to achieve their output, and in these cases it is not surprising to hear that he running costs are extremely high (far in excess of the boiler they replaced) and have been unreliable due to not being plumbed in properly to ensure minimum flow rates are met (these systems almost never have a buffer tank as part of there installation). My system has been in and working faultlessly since I built my house over 8 years ago.

I'm a mechanical engineer by training who has worked in the commercial and residential energy efficiency/controls area for nearly 30 years so have spent a lot of time researching and working with all kinds of heat sources and system designs.

I'm hoping to add a wind turbine next - a 3kW model should be a good match for my heat pump demand (both in output and peak generation) and move me much closer to zero import. Depending on how well that goes I'd be more likely to revisit battery storage. However now that we have an electric car (which may be able to be used to store power and put this back into the local network when needed) we might not need to bother with conventional battery banks in future in any case.