ASHP Consumption
Hi all,
I am getting a new ASHP in a couple of weeks, taking advantage of the green homes grant. We have a 240m2 house, however its heavily insulated. As an FYI we used 36,000kwh of gas last year for heating and hot water - taken from gas use in ft3 converted.
We are due to get a 12kw Midea system to replace the current 32kw boiler. We have 8.4kw solar array and 7kwh of battery storage. I am looking at increasing this by another 7kwh later in the year due to the ASHP. The battery will be key for me, however it can only provide the house with 3kw of peak power. Any demand above this would come from the grid.
My plan is to swap onto a mixed price tariff, probably Octopus Agile or Go and take advantage of the cheap power at night. This way I can fill the batteries and discharge over the day with some solar top up. I will probably only do this in the winter, as the summer months its not needed. However I have struggled to find the expected average power draw from the ASHP. I assume as its a 12kw pump I should get a max draw of around 3-4kW at peak with a COP around 3 in the winter. But this is peak, what kind of draw can I expect post max?
At 3kW I would empty the battery pretty quickly and any extra power would come at normal power costs (not really an issue as the heating is the big taker).
Feedback would be most appreciated so I can start to plan my battery changes.
I don't think its worth investing in more battery power if you are getting an ASHP. It would be more worthwhile to invest in a solar PV to hot water converter like an iBoost to make use of any excess solar (if you don't already have one). During the winter the ASHP will run most of the time and the reduced solar production would all go towards powering the heat pump.
Mitsubishi Ecodan 14kw ASHP + 500l Cylinder
I already have a PV to immersion diverter, however with an ASHP this isn't really worth it. the ASHP will be much more efficient.
On the battery the driver is the cheap rates at night Octopus Go is 5p for a 3 hour period. With a COP at 2.8 this is 1.8p per kilowatt of heating. Being able to store this proves a massive advantage in terms of cost vs 10-14p unit rates on a normal tariff. At 14p I've estimated the heating might cost me roughly £1,500 per year, at 5p its going to be just less than £600. The trick will be eeaking this out in the winter (Dec, Jan and Feb) where the demand is highest.
I’ve seen a few YouTube videos about the Midea - looks a good bit of kit.
I hadn’t thought about batteries feeding the ASHP. I was discussing batteries elsewhere on this site and thinking they weren’t for me. But as I install my ASHP..... But I’m thinking you will need massive batteries to drive the ASHP through the cold day time, and fill them at night. But it is definitely something to investigate. But I’d like to see the maths. And wonder how I will fund 😊
Daikin Altherma 3H HT 18kW ASHP with Mixergy h/w cylinder; 4kW solar PV with Solic 200 electric diverter; Honda e and Hyundai Ioniq 5 P45 electric vehicles with Myenergi Zappi mk1 charger
sPosted by: @bataltoAs an FYI we used 36,000kwh of gas last year for heating and hot water - taken from gas use in ft3 converted.
We are due to get a 12kw Midea system to replace the current 32kw boiler.
The rule of thumb I’ve seen has been total yearly kWh/2000 gives the peak power in kW. It works for us- but would give 36000/2000=18kW. Are you sure 12kW is enough?
@robl I have a Daikin EDL series 8kW/h monobloc for heating only (DHW handled by a Sunamp Thermino ePV210) and my short exposure of winter weather from mid-Feb. onwards this year leads me to think our daily need will be for 25-45 kW/h for milder to cold conditions. Using Octopus Agile, I’ll be looking for most of this energy at the cheapest hours and decanting it into 27 kW/h of battery storage. Two periods pf charging a day might make this feasible. I realise that oodles of Tesla expenditure is not in itself an economic proposition but, I have other reasons to want the security of power when we need it as we have experienced long power outages when we could not heat or eat! Regards, Toodles.
Toodles, 76 years young and hoping to see 100 and make some ROI on my renewable energy investment!
If I may add to my previous posting: I am ‘sticking’ with Agile at the moment as I think the average pence per kW/h works out lower than the fixed low cost periods offered by the other tariffs in the Octopus ‘Stable’ (I like mixed metaphors!) as I am a nerd who in his retirement has time to peruse the 48 daily rates to select the cheapest and thus greenest. Regards, Toodles.
Toodles, 76 years young and hoping to see 100 and make some ROI on my renewable energy investment!
-
New Installation - Grant Aerona 3 + 210L Hot Water Cylinder
23 hours ago
-
Avoid the Heat Pump Villain: Why Low-Loss Headers and Buffers Can Sabotage Your Heat Pump's Efficiency
2 weeks ago
-
Installing your own ASHP - DIY
4 weeks ago
-
How can I programme a setback for my Samsung Gen6 8kW heat pump?
1 month ago
-
ASHP heating issues / error code - advice very much appreciated
1 month ago
- 24 Forums
- 1,404 Topics
- 29.4 K Posts
- 28 Online
- 1,185 Members
Join Us!
Latest Posts
-
RE: Say hello and introduce yourself
One of the advantages of microbore is that it can be ea...
By Transparent , 2 hours ago
-
RE: MCS Heat Loss Calculations
Exactly. Hall, stairs and landing are just another roo...
By JamesPa , 2 hours ago
-
RE: Recommended ASHP installers in Hampshire
@benson If you do speak to Ian, just mention Mike in Re...
By Toodles , 2 hours ago
-
For those users with a Mitsubishi ASHP or AC which they...
By Abernyte , 6 hours ago
-
By Mars , 18 hours ago
-
RE: Aira Heat Pump: Stylish Scandinavian Heating
I've learned some more from my discussions with Aira. ...
By IvanOpinion , 20 hours ago
-
RE: Is this a bad installation and is there something wrong with my Samsung heat pump?
The most you're likely to get from a regulator like MCS...
By Transparent , 22 hours ago
-
RE: New Installation - Grant Aerona 3 + 210L Hot Water Cylinder
@macfxd LLH = Low Loss Header - it's on the right of ...
By MikeFl , 23 hours ago
-
RE: ASHP Cut-off Temperatures: What's Your Setting and is a Your Heating Still On?
@technogeek Yes it does. It's in the field settings
By LeChillou , 23 hours ago
-
RE: New Fogstar 15.5kWh upright solution
Yes, its on 21C 24/7 from end Sept until start of May. ...
By Vince31 , 1 day ago
-
Vaillant Arotherm Settings for New Installation
Im just helping my brother in law with his new 7kW Arot...
By bontwoody , 1 day ago
-
RE: EV charger installation question – I don't want to bury the cable
Hello @hem. And I see that @editor has very quickly fou...
By Transparent , 1 day ago
-
RE: Are Solar Diverters Necessary for Homes with ASHPs and Solar PV?
Yeah, my diverter is off almost all the time since we h...
By Andris , 2 days ago
-
RE: Creating a second zone on Mitsubishi Ecodan ASHP
Thanks for your time with this Gary. I have a wireless...
By BryanB , 2 days ago
-
RE: Error on Immersun – Error 8 Load Short Circuit
@julesmp8 After a whole battery of tests? 😉
By Toodles , 3 days ago
-
RE: Delivering a smart and secure electricity system: government consultation
@abernyte Well, anything is possible, after all, we hav...
By Toodles , 3 days ago
-
RE: Heat Pump Paradox: The Industry's Adoption Divide
@majordennisbloodnok 😆
By Toodles , 3 days ago
-
RE: How to increase DHW water temperature on Samsung Gen 6 Control Panel
@jamespa I have the Samsung high temp quiet model and w...
By TechnoGeek , 3 days ago
-
RE: Need a bit of help please: problematic heat pump installation
Thanks for the replies, and looking back it is a bit va...
By Seagrave , 3 days ago
-
RE: GSHP running UFH but no feedback loop yet.
thanks! It did turn out to be a sort of fault - well, ...
By petew , 3 days ago
Latest Topics
-
By jswhite 3 hours ago
-
By Abernyte 6 hours ago
-
By Mars 18 hours ago
-
Recommended ASHP installers in Hampshire
By benson 19 hours ago
-
Vaillant Arotherm Settings for New Installation
By bontwoody 1 day ago