Jump to content

5 MWh milestone hit


H F

Recommended Posts

Interested in how you calculated the 13 tonnes of carbon dioxide.

There were many times this year when we had very low fossil fuel usage, this reduced the carbon dioxide per MWh considerably.

There are also regional variations. A quick look at intensity.org.uk shows that the South East, where you are, has a CI of 245g/kWh. South West, where I am is 78g/kWh.

So your 5 MWh is worth 1225 kg saving, mine is 390 kg. A third of yours. Makes investing in personal RE for carbon dioxide saving rather marginal.

@Ed Davies is the person that has looked at marginal differences in grid intensity.

Edited by SteamyTea
Link to comment
Share on other sites

Lots of ways to calculate this but whatever, it looks like there's a decimal point slip in there so it's probably more like 1.3 tonnes rather than 13 tonnes  of CO₂.

 

The current carbon index of the grid (total CO₂ emissions / total generation) is not very interesting from this point of view. Generally speaking, low-carbon power sources (renewables and nuclear) do their thing at whatever rate they can manage at the moment then gas makes up the difference. This means that any additional renewable generation (used sensibly) directly reduces the amount of gas burned so should really be “scored” at minus the emissions rate for a closed-cycle gas turbine, not the grid average at that moment.

  • Like 2
Link to comment
Share on other sites

33 minutes ago, Ed Davies said:

This means that any additional renewable generation (used sensibly) directly reduces the amount of gas burned so should really be “scored” at minus the emissions rate for a closed-cycle gas turbine, not the grid average at that moment.

I agree with that.  Though sometimes harder to work out on a time series.

I think it could be worked out from the GridWatch data as that gives generation by type at the 5 minute interval, as well as demand.

 

Link to comment
Share on other sites

1 hour ago, Home Farm said:

We hit our 5 MWh milestone on our solar PV system a short while ago. Almost 13 tonnes of CO2 saved from going into the atmosphere.

 

29F7793B-E65A-40DF-AFE6-205DD5BEEF7A.jpeg

Nice! Thanks for sharing this.  How long was it since installed?

 

Could you explain the various numbers here? I guess 6.16kWp is max power it's ever generated, 3.87kW is current live power?

Was your ASHP running at the time this image captured (or cooker on)? If so nice to  have caught an unusual example of the getting over half of the space heating load  from solar.

  • Like 1
Link to comment
Share on other sites

We’ve been running since March.

 

6.16kW is our full array - max we can produce.

3.87 is what we were producing when I took the screen grab.

6.3 is what we were consuming power wise - that would have been ASHP and dryer running... maybe even dishwasher. So we were offsetting half our power requirement with solar.

Edited by Home Farm
  • Like 1
Link to comment
Share on other sites

  • 3 months later...

Our solar PV panels have been up for just under a year and according to the SolarEdge app we’ve saved pumping just under 1,500 kg of CO2 into the atmosphere, producing 5.7MWh of electricity in the process. Not bad I think.

8452F701-AA78-4D40-84DA-69FD61EA1654.jpeg

Link to comment
Share on other sites

The calculation isn't easy, given the wide variation in grid CO2 emissions from day to day and even hour to hour during the day.  Probably the best way to look at it is to estimate your total household emissions and subtract the emissions saved by the PV generation, to get an idea of the true impact.

 

I was asked to give a talk in our village hall a while ago, about our build (turned out to be surprisingly popular - standing room only).  When putting together the presentation I tried hard to think of a way to enable people to visualise CO2 emissions.  The best thing I could come up with was to convert emissions that were saved, both from designing a low energy house, and the saving from PV generation, into trees.  A mature tree sequesters roughly 20 to 25 kg of CO2 a year, in the form of carbon locked up in the timber.  The SAP calculations for our house give a CO2 "emissions" figure of -0.9 tonnes/year.  This equates to the CO2 sequestration from about 40 mature trees.  All those who knew our site could see that we couldn't possible fit 40 trees on it, so it was pretty clear that our house was, at least in terms of CO2 emissions, less harmful to the environment than if it was planted with mature trees.

  • Like 2
Link to comment
Share on other sites

9 hours ago, MikeGrahamT21 said:

Its Sunny Portal, from SMA, links into my SMA inverter. They even give one solar coin for every MWh I generate, not that they are worth anything at the moment! lol


What are solar coins? Are they like crypto?

Link to comment
Share on other sites

25 minutes ago, MikeGrahamT21 said:

Yeah its a cryptocurrency, they give you one coin for each MWh you generate, but they are worthless pretty much, I suppose theres always a chance they could increase in value, unlikely id say!

That’s what they said about Bitcoin.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...