Renewable energy veteran Ben Hill is widely known in the solar and energy storage industries as the former Trina Solar executive who drove the Chinese company towards a leading position in the European market in the days of the large-scale boom before leaving to become Tesla’s VP for Europe, Africa and the Middle East.

After a couple of years at the helm, including during the launch of Tesla’s stationary energy storage division, Hill left to pursue fresh opportunities. UK start-up Solo Energy is among a number of companies he says he is now working with closely as an advisor. Earlier this year, as his involvement was announced, Solo Energy launched a range of home energy offerings based on distributed energy equipment including energy storage, solar and electric vehicle (EV) charging, backed by business models that seek to derive more value from behind-the-meter solar-plus-storage, both for consumers and for the grid. Andy Colthorpe spoke with Ben Hill a while back to learn more.

From Trina Solar to Tesla, among the more established of the ‘new’ energy and technology companies selling into markets around the world, to a start-up deploying home systems on a no-money-down basis in the UK. What made you take that leap?

I advise numerous companies but Solo is one of the most exciting ones so far in battery storage and the PV space. I’m still doing a lot on large-scale PV and things like this as well, but I met one of the Solo founders, Mark Hamilton (CEO) at an REA (UK Renewable Energy Association) energy storage show a little over a year ago.

There was stuff they were doing which was really taking what I’d seen and what I’d been doing, to the next level. I’m able to help build their company and bring the experience I’ve got internationally, as well as in the UK, because ultimately their supply chain and what they’re doing is truly international. Right now, initially it’s benefiting customers in the UK and Ireland but the plan is to extend that to a greater extent.

I’m surprised to hear there’s already an international focus for the company so soon after pilot programmes and then a commercial launch in the UK and Ireland.

No, the [international] focus is on the supply chain. To be able to get the materials for the sorts of things Solo wants to do, today the UK is not necessarily the leader in residential batteries or V2G (vehicle-to-grid) hardware technology. Obviously, I have the contacts around the world in those fields: battery companies, EV companies, manufacturers and so on.

Indeed, both Trina and Tesla are vertically integrated to a greater extent. What are the dynamics of now working with a player with a start-up mentality – does that allow them to be a bit more flexible around supply chain issues or nimble around business models?

They are extremely nimble. Solo is not a company which started with a plan to do batteries, either batteries on the ground – or the Orkney [pilot] project where batteries are on the ground from different manufacturers and others which are feeding into the Flexigrid platform [Solo Energy's proprietary software platform which allows home systems to be aggregated into virtual power plants (VPPS)].

Right now, for Solo, as the owner and operator of the batteries within their principle business model, the longevity and life of the batteries is more critical to them than anybody. All these different tests we’re doing on different batteries from different manufacturers around the world, also including different chemistries from NMC (lithium nickel manganese cobalt oxide) to LFP (lithium iron phosphate), that’s really critical and interesting stuff to see the real-life tests of those batteries going on.

[Meanwhile] the Flexigrid programme, V2G vehicles can connect to that as well, which obviously requires bi-directional inverters. Then that becomes much more interesting, because suddenly instead of a [home storage] battery which is 10kWh or 13.5kWh you get a 40kWh or 60kWh battery or larger, which you’re able to do things with. That becomes much more interesting.