In film and TV production, the main sources of carbon emissions are transport and energy. When we joined an independent feature in July of this year, we immediately assessed the filming locations to identify opportunities to use grid or mobile power. A four-week period at a disused hospital – where it was assumed only generator power would be used – stood out as an opportunity to reduce fuel consumption and trial batery technology.

With the support and expertise of gaffer Theo Milford, an E-vis 150 kVA battery backed up by a 100kVA Stage 5 generator was used to power the set lighting for four weeks. 

E-vis is a UK-based clean energy solutions service for the screen production industry. Through their partnership with Zenobe, the largest owner and operator of EV buses in the UK, E-vis provides award winning second life batteries to reduce the reliance on traditional diesel generators in the Film, TV and Events sector.

We spoke to Theo about his experience:

The idea behind a hybrid battery set-up is to reduce fuel consumption – how does this work?

All power is generated by the fuel generator. However, fuel generators operate at peak efficiency when operating at 70% load, a greater or lesser load means less fuel efficiency. The battery can provide any level of power with >95% efficiency and the fuel generator when recharging the battery always operates at peak efficiency. The hybrid system ensures however much your load varies, the fuel is burnt with maximum efficiency. Moreover, whilst the battery outputs 3ph power the loads don’t have to be well balanced, as each phase of batteries uses all 3 phases of the fuel generator when charging.

How did you find the process of syncing the battery to the generator?

Set up when it was delivered. Very similarly to a sync-set from other suppliers.

It was your first time using this technology, did you have any apprehensions going in? How did you deal with any worries from your team or the wider crew?

I spent a lot of time in prep talking with various generator and battery suppliers making sure I understood the strengths and limitations of the equipment and that it was suitable for our purposes. The crew weren’t convinced as to the benefits but were happy to try new toys.

Once the battery was up and running, did you notice any benefits?

Silent running, not having to worry about balancing the phases, being able to leave running 24/7.

Were there any challenges or issues that arose during the trial period? How did you tackle them?

The user interface isn’t particularly intuitive and the startup time is considerably longer than a standard generator (approx 5 min rather than 1-2min). So, after the first few days we set it so the generator wouldn’t kick in during unsocial hours and left the battery running continuously.

What would you say to a fellow gaffer who is weighing up whether to use an electric battery?

I’m sure anyone will do their own due diligence when looking at power options. This system was suitable for our main location, but not for the other locations on the job. Your experiences may vary, but the benefits outweigh the cons in my opinion.

What recommendations would you make to battery companies, to make their technology more suitable for film and TV shoots?

To make the system more mobile, secure and ideally with an additional physical load bearing facility. And to make the user interface more intuitive if possible.

Over the 4-week period, the battery powered the set for 80% of the shoot (battery run time: 522 hours, generator run time: 104 hours) reducing the amount of fuel used by an estimated 45%. Compared with a standard generator running on diesel, this equates to saving 2675kg of CO2 emissions and £1,526 in fuel costs.

Battery technology is advancing at a rapid pace in the UK, and there is potential to see dramatic emissions and cost savings by charging batteries from grid supply overnight to power sets or bases during the day.

Find out more about E-Vis batteries here: https://www.e-vis.org/general-2