The UK's first ever diesel vs hybrid-electric narrow boat performance trials set to reveal interesting comparison data including a test of HVO diesel


A fleet of narrow boats powered by a mix of hybrid-electric and HVO-diesel-fuelled engines are set to ‘race’ each other along a stretch of the River Severn and the Droitwich Canal this weekend.

Eight boats will set off from Worcester at 0900 on Saturday 29 May heading north up the River Severn, through Bevere Lock, then turning east at Hawford Junction onto the Droitwich Canal and winding their way to Droitwich Spa marina – around 13 miles in total.

A traditional diesel-powered narrowboat, Here We Go Again, will be the benchmark by which the other seven boats will be compared in terms of handling, speed, acceleration/braking and consumption.

There will be five diesel-electric hybrid boats and two other diesel powered narrow boats taking part in the trial.

The three serial-hybrid boats will be comparing performance data with the two parallel-hybrid boats (and with Here We Go Again), while the two diesels will be doing a separate ‘head to head’ comparison with one using conventional red diesel and the other using the latest hydro-treated vegetable oil (HVO) fuel supplied by Crown Oil.

What is HVO fuel?

The trials have been organised by Ortomarine, which has, to date, built 3 all-electric canal boats, 3 serial-hybrids and 7 parallel-hybrid boats.

‘Individual boat data is interesting, but Ortomarine have always wanted to do a comparative test, looking at how each boat performs in a typical 8hr cruising day,’ the event announcement states. ‘Each of the vessels taking part in the trials, will follow the same route, on the same day and in identical conditions to provide the most objective comparison of the different designs.

‘This trial hopes to show that in performance terms HVO diesel, matches conventional red diesel, but reduces greenhouse gases by up to 90%, does not suffer from diesel bug and can be stored in the fuel tank for up to 10 years.’

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Paul Sumpner, owner of Old Nick, one of Ortomarine’s most recent Serial Hybrid narrow boats told PBO:

“We are going to start at Worcester. It’s quite wide on the Severn there, so we should be able to start off [all eight boats] in a couple of rows – three or four perhaps. And then naturally the electric boats will be at the back and the diesels at the front. The diesels will probably power on ahead. We were out last Saturday [on the River] and we were having to struggle against 2-3mph of current. There had been a lot of rain – the river was on amber alert. The following day (Sunday) it went to red alert, so we wouldn’t have been able to go out. This weekend is going to be much better and calmer.

“Bevere Lock takes two boats at a time so we’ll get through that fairly easily. We’ll all be going against the flow on the river for about 90 minutes – so a good test for the electric engines in particular – then we turn in at place called Hawford which takes us onto the Droitwich Canal. Initally it’s a barge canal with double locks. Then when we get up to Droitwich Spa it goes down to single locks. Then we’ll all meet back at Droitwich Spa marina to compare notes, dust ourselves off and have some pizza – that’s the plan.

“We’ve got a series of trials planned for the day. So we’ll be testing how much [electric] current draw at different miles per hour on the river. So we’ll all start going at 2mph, then up to 3mph. As long as there’s not too much flow we should all be able to reach 4mph. Diesels will probably go a bit faster after that. We’ll measure how easy it was to get to those speeds. What current draw on the electric engines. Those are the first trials. Also, when we’re back onto the actual canals where it’s a little bit easier to have people on the towpath to measure distances, we’ll do an acceleration test: 100-200 metres from a standing start to see how long that takes. And then conversely we’ll also get to a walking pace and on a signal from someone on the towpath we’ll put the boat into reverse and see how quickly they can deccelerate and come to a stop.

“We’ll all be connected to the cloud. We’ve all got Victron systems on board, so we’ll be able to measure on a minute-by-minute basis the sort of current we’re taking from the batteries, the charge of the batteries, see when generators are run, things like that. And when we get back to the marina we’ll measure how much diesel each of the boats has used.

“Unless it’s a really hot day on Saturday, which it doesn’t look like it’s going to be, it’s unlikely any of us will get round just on solar. I think with the flow on the river for the duration of the day we’ll all have to run our generators at some point.

“We’re not telling people how to cruise, so everyone will go off in whatever cruising pattern they follow, so there will be some people that go along slower than others. It’s really just to get good consistent comparison between different boats on the same route in the same conditions to give real-world feedback on what’s achievable with the latest generation of hybrid-electric installations.”

“All the boat owners have chatted to each other online, but I don’t think we’ve all met face to face before. So that will be nice to see everyone. CRT are sending a representative. The IWA have a couple of people coming, Graham from Hybrid Marine who makes parallel Hybrids is coming along. Crown oils who do the HVO…”


“Vetus have not given the go-ahead. A lot of engine manufacturers have said they’re good with HVO, but Mitsubishi who make a lot of Vetus engines and generators Haven’t given the green light, but I think they are evaluating the possibilities. We’d like to use it in our generator – it’s the least green bit of the boat.”

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