Your tech and how it works for you

Hi Bruce

That was exactly what I was looking for when asking for real life experience in using tech. When you say ‘I’ve done this and it works well’ it’s helps other people be confident in following in your footsteps.

One of my concerns was the relative lack of competency in designing a heat pump system. You had the experience of being recommended a 10kW system but having a 7kW pump installed and it working well. The advice is get a number of quotes and ask questions as to how certain that is to be correct. It’s also a good comment on the relative prices of the two systems. It’s very hard to get true before and after comparisons and I pleased that your experience was very positive.

Unfortunately the ratings of gas boilers is no indication of what you actually need. Mine is an 18kW Vaillant Ecofit but my absolute maximum requirement is about 100kWh per day or only about 4kW continuous for a few occasions. When an ASHP engineer turned up to do a survey he looked at the property and said ‘I think this a 5kW job’ which was spot on but when he had entered the data he said it needs a 7kW system with much higher costs. I rejected the quote because I believed it was flawed and DIY installed a 3kW, A2AHP instead and supplemented it with a bit of wood burner, gas and some solar gain. The house was really warm last winter and it was colder than usual. It doesn’t do any harm to look at alternatives instead of just blindly following what your neighbour did or someone on a website said without any context or feedback.

As a bit of commentary on the chart below the gas (blue) was really only used on the coldest days and I only used 20% of what I would have used that year. The A2AHP has taken the base load and I used the wood burner (brown) to cover my peak electricity prices 4-7pm. I also experimented with 4kW of fan heaters overnight when my electricity prices were zero (happens on Agile) and turning the lounge into a heat battery. Didn’t happen that often (only 3% of total heating) to make any real difference though but it caused the heat pump and gas boiler to shut off completely for quite a few hours afterwards. Also, 6% of my heating is solar gain through our large patio doors and window.

Many thanks for your comment.

Peter

Thanks Peter, I have to say the OVO Heat Pump Plus tariff has been great ,15p kWh for all electricity used by the heat pump was a game changer and will probably keep me as an OVO customer. I also have a wood burner which I can use to top up on the coldest days, but not really necessary. My Heat pump also has an option of a top up heater (simple immersion heater for the space heating). I don’t have this option and don’t need it.

I took a while to get my head around leaving the heat pump on all day and night to keep the house temperature constant. But once I tried it I would never go back to on off gas boiler heating. 

Getting a competitive tariff for a heat pump  is an important point. My average domestic rate is about 19p and that makes my heat pump cheaper than gas. In fact I not only reduced my gas use it was also cheaper by about £125 over the winter. That is what I mean about going green but also being affordable. In this case it was a win win. The equivalent electricity price for a heat pump is:

Gas price x HP COP / Gas boiler efficiency

In my case it was 6.2 x 3.6 / 0.9 = 24.8p

Which was 24.8p. On Agile that was basically any time of day apart from the 4-7pm peak.

Bruce

I've just seen that Scottish Power have dropped their SEG rates from 12p to 6p. With more solar farms coming on line and especially the huge Botley West scheme then SEG rates will come under pressure and perhaps a drift towards time of use rates with higher values during the evening peak which will favour west-facing panels.

https://www.bbc.com/news/articles/clyj42pd15go

Peter

Thanks for sharing this ​@Peter E! 

What’s your take on the scale of the project? 

At 840MW it is massive and there have been protests over the size of the scheme but here is my personal take on it.

For the first time in thousands of years the area will be the sole domain of wildlife. No people, no cows, no sheep no yearly ploughing of the land, no nitrate fertilizers or nitrate run off into rivers, pesticide, herbicides or destruction of wild flowers. Other schemes have reported a huge increase in wild plants, insects, birds and a refuge for larger animals. It's big enough for a mini ecosystem with wildlife corridors where small animals could live out their entire lives without being aware of the boundaries. And it generates carbon free power. This maybe the change that partly reverses wildlife decline. The negative is that it will tend to reduce the SEG rate.

Even though I don't have solar panels I benefit greatly from solar power production particularly when there is a bit of wind blowing 

This is an extreme example but most days now I'm seeing a large dip in prices in the afternoon during the week which didn't happen so much last year. The downside is the 4-7pm peak and you have to keep your eye on prices and winter rates can be eye-wateringly high.

Peter 

Morning ​@Peter E, 

It's an enormous project, and I understand why people are hesitant; change can be a scary thought. I wonder what was said when the first wind farms were built—now they're just a part of our lives. Perhaps we could combine the solar panel farm's implementation with the establishment of an official wildlife sanctuary to protect the ecosystem. It would be amazing to see a population boom in small animals, especially since we've increasingly encroached on their land, leading to a decline in some species, as you've rightly pointed out.

The inherent volatility of flexible pricing is such that comfortable rates can rapidly become prohibitive if one isn't vigilant. Is it possible to configure alerts, for example, "prices increasing by XX," to provide advance warning, or does it necessitate constant monitoring?

There’s a lot of it about - new planned solar installations (they are by no means farms) are the current ‘comming thing’; as of course is local protest against them.

https://www.bbc.co.uk/news/articles/cp91yvpvlr7o

I have to say it does seem to make less sense up here in Cumbria, wind turbines are better suited and we have plenty of those already, such as Robbin Rigg in the Solway.
https://en.wikipedia.org/wiki/Robin_Rigg_Wind_Farm
There is also plenty of onshore wind generation too, but that tends to be smaller less visible sites.

For the last 2-weeks while the South has had a heatwave, here in NW Cumbria we have had almost constant cloud cover, rain, and the occasional thunderstorm.
And yes; lots of wind.

​@Chris_OVO and ​@Nukecad there is a place for appropriate schemes wherever you are. On the train down to Exeter from Salisbury you pass Crewkerne where there are acres and acres of solar panels, the ones at the bottom near the line stand in water where there could be no other use for the ‘land’.

As for getting alerts, this is already possible with wholesale ‘day ahead’ (Agile) prices where the price is already fixed 24 hours in advance so with something like Home Assistant reading these prices you can schedule power use / storage at very low rates without any manual intervention. Automation is the key to flexible power use. You can also get predictions for solar and wind generation so you can get even more advance notice of when rates are likely to be favourable.

Coming on line soon and phased over the next year or two is the Dogger Bank A, B and C wind farms rated at a total of 3.6GW. That will create an even bigger and sustained hole in the rates.

I'll provide a link to the various resources that I use when I get back. Assuming I get back. The French Air Traffic Controllers have gone on strike today for our return flight < sigh>

Peter