Home charging and the OLEV incentive



Hi folks - so I was looking into adding a home charging plug in the form of a Menekes 2 Rolec unit for the front of the house. With the great OLEV grant, which pays for 75% of your installation up to 500GBP, I would only have to pay 150GBP for the installation. But wait - it is NOT that simple!!!

The surprises come from the home itself. The Renault Zoe requires a VERY good ground wire and it is very sensitive to it (“Charging is Impossible” message can arise, and can damage the car if not grounded well). The requirement is to have a ground with less than 100Ohm… which can lead to have a copper bonded grounding rod go down by up to 30ft if your soil is not that good as a conductor. Grounding is not as simple as it seems, and the methods can vary from chemical grounding (uses this conductive gel to surround the rod), to grounding copper plates and conductive concrete. Either way, this is not part of the installation scope of the OLEV grant and will be charged to the user.

Next up - if you want a 7.2KW delivery (about 30Amps) which will be about 3x the delivery of your 3-pin plug alternative of 10Amps, your home has to have at least an and 80 Amp fuse, or 100 Amp. Now that’s that big black box next to the meter as the current enters the house, and is owned and operated by your distribution company. 100 Amp if you have a lot of draw on the house with many electronic appliances, 80 Amp if you have few appliances. If you have a 60 Amp fuse, then your option is to go with a 3.6KW delivery for your Rolec Menekes 2 plug, and that’s only 15 Amps of juice - not much better than your 10 Amp 3-pin plug alternative. Here is the rub… you want the 7.2KW delivery, the distribution company may say you need 100 Amps after they survey the house, and to get that they will have to upgrade the cable coming into the house to get that draw. Only costing you thousands to dig up the street/pavements to do so.

Conclusion - Cost benefit analysis rules… if you can’t get 100 Amps, don’t bother to even scope the grounding issue. If you can get 100 Amps, then see if your grounding can reach 100 Ohms. Most homes will not get that type of low resistance from their current grounding. There is no way to predict by a survey how long the rod has to be to get that 100 Ohms. The electrician charges per rod, so if you don’t meet the goal, another 4ft it goes, and you get bit by another 75GBP. Given ASDA is 2 miles with a free 7.2KW charge point, and having a 3-pin plug solution already… the 7.2KW Menekes plug at home is looking pretty unlikely. It took time to uncover these hidden costs - as they entice you with a simple solution for a low cost, then science and reality hits. Not a problem for a Twizy - but for a Zoe, it got complicated. :disappointed_relieved:

I tried one vendor for a ChargeMaster solution, and they got fired for mere incompetence in their planning and approach to deliver a good solution. I went with Rolec the second time - and went through the proper process of evaluation - this gave the clarity of what kind of job it really is, not just a simple box on a wall. So I guess if anyone got any ideas on the main fuse and grounding that’s cost effective, please let me know. Otherwise, the 3-pin plug will be the solution :slight_smile: