LnP

Great blog and nicely written. Regarding goggles misting up, the mist is tiny droplets of water condensing onto the lens. If you put something on the lens which breaks the surface tension of the water droplets, they all merge into a continuous layer, which you can see through. Dilute detergent or soapy water works. Dilute baby shampoo won't sting if it gets in your eyes. Licking the lens can also work .... depending whether you like the taste of dusty goggles!

I think I posted Warrington's UU elsewhere, but here it is again. I'm not a lawyer, but a couple of differences I noticed: Warrington provide for the possibility that the self builder could be released from their obligations if their circumstances change. Unless I missed it, Dorset does not. The Warrington UU says: "PROVIDED THAT the requirements in paragraphs 4 and 5 shall not apply in the event of a change of circumstances acknowledged by the Council in writing acting reasonably which prevents the Original Owner from Occupying and/or not Disposing of the relevant Dwelling within such three (3) year period." I'd be thinking about ways in which my circumstances might change, for example my place of employment changes, I lose my job and have to move house, I need to move closer to aged parents, I get sick and need to move into care, etc. It looks like the Dorset UU would prevent me from doing that. In the Dorset agreement, your self build has to continue to be your "sole or principal residence" for three years. Does this prevent you from owning a second or holiday home? None of this is legally required by the Act or Regulations. The self build exemption is provided in The Biodiversity Gain Requirements (Exemptions) Regulations 2024. They very simply exempt self builders. And self builders are simply defined in the Self-build and Custom Housebuilding Act 2015, Local authorities are over-reaching their legal mandate. I continue to believe that the way they're implementing the self build exemption is outrageous. Warrington Self Build - draft UU26.9.24 - FORMATTED 16.10.2024 CLEAN (1).docx

You can't beat the second law. Once you've converted the electricity (work energy) into heat energy, any device you design to get back to work energy can never get you back all the energy as work. Some energy will always be rejected as heat. The best you can theoretically do is a Carnot heat engine which has an efficiency of (Th - Tc )/Th - hot and cold temperatures in Kelvin. And there's no actual such thing as a Carnot engine. Yes, great if you can find a use for the rejected heat. I've got a fantastic energy project I think you might be interested in investing in ....

At the moment, curtailment is usually because the grid doesn't have sufficient capacity. We should spend the money on increasing the capacity of the the grid so it can handle all the wind and solar, rather than expensive energy storage just because the grid can't handle it. Eventually though we will need storage to balance supply and demand. How to manage intermittency and curtailment was studied by the Royal Society and reported here, and indeed they found a potential use for hydrogen, i.e. renewable electricity via an electrolyser to hydrogen, stored in a salt cavern and back to electricity by a fuel cell or ICE and generator. It's expensive both in terms of capital cost and the round trip efficiency of 41%, i.e. you only get 41 kWh of electricity back for every 100 kWh of renewable electricity you put in. Back to my original point though, advocates of hydrogen who don't understand the thermodynamics will assume that we can improve on the 41% as we get better with electrolyser and fuel cell technology. I'm afraid lobbyists and parties with vested interests looking for subsidies, exploit this and persuade politicians that the economics will improve. We can't and they won't. These are second law losses and you can't beat the thermodynamics. Some people correctly argue that interconnectors, which were not included in the RS study, could be a better solution - you connect to renewable sources where the wind and sun blow and shine at different times. Interconnectors avoid second law losses. It all about the difference between the two types of energy, heat and work!

Power is to work as speed is to distance 🙂. One is the rate of the other.

I don't understand your point about enthalpy. Did you mean entropy? Either way, there are different ways to state the second law. I tried to make it simple and deliberately didn't bring entropy into it. I just saw something which was incorrect, is a common misconception and incorrect in a way which sometimes leads to poor energy policy making. So I hoped to straighten that out. A political example ... if our politicians understood this science better, they wouldn't be wasting tax payers' money on subsidising projects which use hydrogen as an energy vector, for example this one in Aberdeen, especially given that in Montpellier they already learned the hard way. Compare: Renewable electricity -> hydrogen (heat energy) via an electrolyser -> electricity via a fuel cell -> work energy via an electric motor .... or -> work energy via hydrogen internal combustion engine. Versus: Renewable electricity -> work energy via an electric motor in a BEV. Apologies if this has hijacked the thread!

No. Heat and work are the two different types of energy, measured in Joules. Power is the rate of doing work measured in Joules per second. A J/s is a Watt. The first law (conservation of energy) is easy. The second law is tricky. Politicians don’t understand it which is one reason why we get incoherent energy policies.

Actually not correct. Second law of thermodynamics, there are two types of energy, heat and work. Work can be converted completely into heat; but heat cannot be converted completely into work, the best you can theoretically achieve is a Carnot heat engine. Fossil fuels provide heat energy and electricity provides work energy. The second law is not well understood but important in the context of plotting a course to net zero.

Is this because the BNG gains cannot be legally secured through a 30-year monitoring plan in a private garden? @Benpointer, so what are you going to do? What conditions are in the proposed S106 agreement? I'm more concerned about ecologists setting up biodiversity offset sites, because they on the one hand tell you how many points you have to buy and on the other sell you the points. A clear conflict of interest. This is a mess.

@Benpointer Since you have plenty of space to add the 10% biodiversity points, you might be better off foregoing the self build exemption, with its associated costs and S106 restrictions. I’ve heard a habitat survey and assessment costs about £2k. Its another irritating and unnecessary professional fee, but being pragmatic, maybe the BNG self build exemption is more trouble than it’s worth.

+1 for FH Brundle. If you open an account you can sometimes get a discount.

... not to mention the costs you'll incur to implement and monitor the S106 agreement. Have they told you how much that will be? It seems some LAs are using UUs and some S106 agreements. Maybe some are still accepting a signed letter declaring yourself as a self builder. I'm not familiar with S106 agreements, but will the agreement prevent you from selling your house for a period of time, e.g. 3 years, after completion? Do you need finance for your build? If so, what does your lender say about this restriction? I've heard some lenders won't accept it. It's worth considering whether it might be cheaper and easier to do the BNG assessment and agree to the mitigations required to achieve the 10% net gain. Be careful though if you go this route. I recently saw a small garden plot where the proposed house would cover most of the plot and leave very little space for adding biodiversity. So they needed to buy offsets to replace the lost biodiversity points and the required 10% additional. The ecologist company which did the assessment also operates a biodiversity offset bank and were - surprise, surprise - more than happy to offer to solve the builder's problem by selling them offsets ...... for £36,000!! It's a huge conflict of interest with no checks and balances. So if you decide not to avail yourself of the self build exemption, it might be better to use an ecologist who is not selling offsets. LAs say they are ensuring that sneaky commercial builders are not dishonestly using the self build exemption. But the number of self build planning applications is tiny. Is it really necessary to go to these lengths and in many cases close the door on the exemption. How the self build BNG exemption should work has not been thought through and is unfair to self builders.

I wanted to paint a screeded workshop floor. The small print on the solvent based floor paints I looked at said they weren't suitable for screed, only suitable for concrete. So I went for the two part epoxy paint. Yes it was expensive and you have to discard your rollers and brushes afterwards, but I preferred to do the job once. It's been down a couple of years now and is holding up wel ... l and I like the high gloss finish 🙂 . I've dropped things on it and it hasn't chipped.

Are you claiming the self build exemption from having to demonstrate biodiversity net gain? If so, are the LA doing anything to prevent you from subsequently selling? My LA require us to sign a unilateral undertaking and will put a charge on the house to prevent us from selling in 3 years from completion.

Why so?