SteamyTea

Basically you have a choice of two systems. An electrical, in line, resistance heating element, or a fluid filled 'radiator'. The electrical one is easy, it just plugs into the mains, the other is then really up to you how you heat the fluid. But if you are using an ASHP to heat your domestic hot water, it can be 'tapped' off that system. Some MVHRs (Genex for one) have a build in heat pump to add to heating and cooling. This is really two questions. How does a heat pump work in practice? and what is the best way to control the complete system? At its most basic, a heat pump has a hot side and a cold side. The plumbing within the heat pump will control which side is piped into the house. Basically there is the refrigerant pump, then, via some heat exhangers, some pipework to a radiator (the air source bit) that is outside, and some pipework to inside the house (the source or sink) for space and\or water heating. Just a case, depending on what you want, as to how the control valves reconfigure the heat exchangers. As for the house heating controls, this is a bit more complicated as it is very much dependant on the shape of the house and the usage. It is usual to zone areas and control each zone separately. That way you can have different temperatures, at different times for heating or cooling, is on and in different places. What many have found though it that having just one zone for the whole house is often good enough, and can be used to move excess heat around if needed, without using the heat pump (just pump the water in the UFH about). One thing with heat pumps is that they need to be designed correctly for the expected heat loads. This usually means over sizing them as that keeps the coefficient of performance up. Most modern ASHP have variable speed motors in them that accommodate this. It is also worth getting to grips with the difference between temperature, power and energy. They are not the same thing. You can have high temperature, but low energy and low power, low temperature and high energy and power, high or low power, medium energy and variable temperature. All a juggling game.

He better sue his installer, MCS and his DNO\meter reading company for this.

Good point. May check when I get home.

Could you fit a diamond saw to a cheap table saw. Then saw the existing bricks in half. My large angle grinder cuts through most things with the cheap diamond blade in it.

If you are considering UFH, how much insulation are you going to fit under it. Heat loss to the ground is greater with UFH than radiators or forced air systems. If you fit post heating to your MVHR, chech that the airflow is large enough to transfer enough energy. It is easy to put in larger ducts at the design stage. You mentioned 'thermal mass'. This is a contentious term and has no basis in science. What you actually mean is thermal inertia, which is the product of the specific heat capacity and the thermal conductivity. What that boils down to is the time it takes for the air in the house to drop by 1°C when there is no extra energy input i.e no heating. Brick and concrete are not very good, timber and cellulose insulation are very good.

How about a bad arable field, or one that is used to grow flowers on, or maybe just to keep pet horses. And that if before ex farmland is turned into golf courses. One thing that we don't have a lack of in the UK is land. We just have a system that stops us doing much with it. This may well change if we change our farm subsidies, but I am sure the new system will be fiddled, abused and not fit for purpose.

Show us your evidence to the contrary. That same link shows UK data to.

Does it now. https://data.worldbank.org/indicator/SL.AGR.EMPL.ZS

Not many people employed in farming these days, and there will be a lot less over the next few years as automation takes over. That is why it needs to be done properly, rather than this silly piecemeal system we currently us. Take @joe90, he is just on the Devon side of the Tamar and has a completely different planning policy from 3 miles west. Segmenting to tiny areas are not the way to plan longterm as any vision is totally lost.

Point out that many local services are under used. Take schools, 36 weeks a year for a few hours, five days a week, 6 hours a day. About 12% of the time. Doctor's surgeries are similar, but higher at 35% of the time. Until recently, my local Tesco was running at around 85%. The supply chain runs 100% of the time. We really under utilise many public assets. Take the water system in the SW, it is about 4 times larger than it needs to be, just so it can cope with 8 to 12 weeks of the year. Electrical grids are the same. 60% of the time I draw nothing from the grid. Environmentally we don't want isolated housing, we need to expand towns and cities, but properly, rather than just cram people into small properties, we need to increase the urbanisation land area (currently about 2% for housing and 10% urbanisation). There was a bit in the papers about people wanting to move to rural areas because of the COVID-19. Noticed that the estate agent across the road from work only has the very expensive houses in his window, not the cheaper, ordinary ones, he has hidden them.

But the overall wind speed is still lower for the height compared to if there was no building at all. This is what they are sold on, but the performance is rubbish, and always will be. Small (sub 250 kW) wind turbines are generally rubbish, much better to stop mucking about and only install large (>5MW) A few years ago I counted up all the sub 100 kW turbines in Cornwall and found that they could have been replaced with just one 2 MW one. It would have produced more energy to.

In my garage, I want all the Pirelli calendars ever made.

Did not think price was important. Ask @pocster how much his stuff cost when he charges himself 50p an hour.

Is it now, or is there some technology that is looking for a solution. I suspect that part of the reason that there is not a decent, reasonably priced system that is readily available is because there is no market. It is such a niche product, that needs to have infinite customisation, that the only solution is a home built one.

My 200 quid laptop has a build in UPS, just like every other laptop. It also comes with a well understood, reliable and supported OS, cheap of free applications, ports to add things to etc etc. Still it i good to have a hobby.

I am intrigued with this conversation, seems to centre around lighting. How necessary is it to remotely control lighting? This is not the same as suitably designed lighting. I think dnb says it best. There is a simple solution to this, 2 kWh battery storage charged by your PV. Has the advantage that it can also be charged at any time when energy is cheap, even if the washing machine is running.

Other way around, I take their money. Rob them blind with patter about Mermaid, krakens and expensive parking.

Admitting defeat already. Shame on you.

Purely out of educational interest. Keep a log of how much time all this takes you to set up and maintain, then, once it is working, start a second log on how much time it saves. Then post up the results if you are brave.

Module degradation is a peculiar thing. It has been known for some modules to improve with time. I suspect that was misreporting though. As for your best day every. That is probably a combination of irradiance, temperatures and time. Just a lucky combination on that day.

Do a time series based cost analysis. Taking Thames water as an example, water and waste currently costs 2.28/m3 Using an inflation rate of 2%, it will take 64 years to get to £8/m3. I currently pay, down in the South West, a gnats over that at £8.083.

That is about 1Wp a year on a 250Wp module. What many manufactures actually do is select the best batches of modules, say the ones that are actually rated at 265Wp on the standard tests, label them as 250Wp, then charge a premium for them. This leaves you with a 238.5Wp module, which is performing at 95.4% of the what you thought was a 250Wp module. Trouble with this is that for a few years, your system will seem to perform better than expected, then eventually drop off. So you may be better off just looking at slightly better performing modules, rather than ones with a warranty. Some of the 'cheap Chinese' modules are identical to the more expensive 'USA or EU' made ones. Thing is, they are often the same product, from the same factories, made with the same materials, on the same machinery, by the same people etc etc. Just the testing and labelling is what sets the output, not the quality, or price, of the product.

Being able to easily add to a system is useful. Stecca used to do an inverter system like this. You bought a 2 kW inverter that had all the controls in it, then just kept adding extra 2 kW basic inverters to it. And it kicked in once the module string was generating 80V, which meant it actually generated more kWh than a comparable SMA system.

Realistically it is not that often that a PV system delivers at full power. It is easy to get carried away with the weather we have been having the last couple of months, but think back to last October, November, December and January.

Amy be worth reading though this short document as it gives some general details, and where to find more indepth stuff: http://www.inbalance-energy.co.uk/further_reading_books/pv_installers/Guide to the installation of PV systems_2nd Edition.pdf It is a decade now since I was involved in PV, but as far as I can remember, and what I have heard from some installers, two things have changed. Inverters are not allowed in lofts anymore and the system capacity is set by total module capacity. But as usual, there is probably more to it this this, the so called 'gotchas'. One thing that is interesting is that inverters need to have isolators on both the DC and AC sides. Not sure how that is implemented with micro-inverters. Be a lot of switches.