Is iBoost really worth it?

Screwdriva

QrizB said:

I usually look at https://electricinsights.co.uk (although you might be able to get the same from eg. https://www.carbonintensity.org.uk/ )

Looking at the last 12 months, the average is 177g/kWh. Breaking it down into seasons:

• Winter 21-22: 171g/kWh
• Spring 22: 181g/kWh
• Summer 22: 196g/kWh
• Autumn 22 to date: 164g/kWh
  

So in the summer, when you're most likely to be generating excess solar electricity, the grid is roughly as dirty as directly-burned gas.

I guess I should explicitly state that, as more renewable generation comes online and the grid becomes cleaner, so the grid carbon intensity will fall and export will become "less green" compared to displacing directly-burned gas.

Exactly as I suspected. And I expect the UK's disproportionate skew towards wind energy will make Autumn/ Winter periods much cleaner in the imminent future. Sadly, the government's lack of focus on solar means that summer months will remain dirty for the foreseeable.

Unless the UK achieves > 50% of Solar generation (our 2022 peak was ~21%), we will never reduce carbon intensity of the grid for ~6 months of the year. With ~4% of UK households equipped with Solar PV, the potential is massive if they get the incentives right. 

ispookie666

Living next to a huge solar farm, 20 wind turbine and a CCGT;  I'll heat my hot water 
Possibly seasonal variation in electric prices might be the correct incentive for going green - More solar and ASHP.  

EcoScruples

eddi installed, not enough solar to use ut until probably March but it costs me about £200 a year to heat my water with Oil so I'll recoup that in a couple if years.
So yes if you're on oil it's worth it.

Boffinboy24

If considering iBoost for eco / gas reduction reasons, then I am experimenting with an alternative designed to reduce my overall gas use that sidesteps the cost of a diverter and some of the issues others describe.

If you have a system boiler (ie with hot water tank) and a modern insulated house, you can make gas heating much more efficient by reducing the flow temperature. But for many systems this means colder hot water as the boiler may not have a separate hot water temp (which means changing mixer tap settings, and could cause legionella concerns for vulnerable people). 

I have managed to reduce my boiler flow temperature to 45 (from 60), and then am using a Wi-Fi controlled immersion to heat the tank on E7 before we get up and shower in the AM. The Wi-Fi controller cost £45. Given the efficiency of the electric immersion vs the boiler it’s also not much more expensive per kWh to heat water on E7. I don’t have enough data yet in the heating season, especially with the warmer November, but early gas readings on these colder days suggest I am using quite a bit less than last year (and not just from the small amount used to heat hot water).