Energy

This blog is a collection of my thoughts on energy, I'm no expert but I hope it provides some utility for anyone reading this. Much of it could be wrong so be careful.

 

Goals

 

1. All devices should be powered by electricity. No gas, oil, petrol devices, cars or garden tools.

2. 90%+ of all electricity from the PV (self consumption not including export). Preferably 100%

3. Chemical batteries used as little as possible with load shifting / heat storage being the preferred route.

4. Chemical batteries to provide fast response buffer to prevent shading causing appliances (e.g. ASHP) to toggle on and off rapidly 

5. Cars and house batteries should be charged directly from DC (SolarEdge have batteries and an EV charger that can do both)

6. TOU tariffs should be utilised to keep bills as low as possible / reduce load on the grid in peak times.

7. Export should provide enough money to cover the water bill + any grid import.

 

Method

 

Energy Efficiency:

* High performance glazing and frames with low e glass to prevent overheating.

* Insulated shutters on all windows for cold winter nights and hot summer days.

* Reasonable air tightness (0.5 ACH target)

* Low average u-rating for building

* MVHR

* Air-source heat pump

* Sewer heat recovery (worth it?)

* Ruthless focus on efficient appliances.

* Utilise waste heat (for example run fanless silent compute at the edge not a big server rack to benefit from the distributed heat)

 

Load Shifting:

* Hydronic underfloor heating on all floors

* Large volume of stored domestic hot water (300 litres +)
* Pool as store of energy (heated when we have supply not on demand)

* Intelligent control of high load devices e.g. car chargers

* Weather aware DHW heating / cooling / shading system

* Batteries will charge when grid is cheap / low carbon with intelligent control (also solar forecasting)

 

DC:

* The PV array can have 200% DC to AC oversizing

* Car chargers will be DC-coupled (SolarEdge Bi-Directional DC EV Charger or similar)

* Home battery will be DC-coupled (SolarEdge EnergyBank or similar)

 

Photothermal (maybe?):

* Explore the use of solar assisted heat pump (e.g. using PT to pre-heat)