It can hardly have escaped readers’ attention that there is a fuel crisis. It is worldwide. The Strait of Hormuz, at time of writing, is blockaded by both Iran and the US. It shows no sign of reopening and, when it does, it will be several months at the very least before tanker traffic and oil flow returns to stability. Consumers are realising this. One response is that demand for oil is reducing.
The International Energy Agency has made large cuts to its forecasts for global oil demand and supply, citing the disruption in the Middle East. It is calling it ‘the most severe oil supply shock in history’.
The agency says that ‘demand destruction’ – a permanent decline in consumer demand that will not return to previous levels – will spread as ‘scarcity and higher prices persist’. Global oil demand is projected to decline by 80,000 barrels per day in 2026, a sharp contrast to the forecast of only a month before that had predicted a 640,000 barrels per day rise.
Simultaneously, prices are rising. The price of oil saw its largest ever monthly gain in March 2026. Oil price volatility is extreme, but above or only just below $100 a barrel is around the current average.
This would seem a very good time to reduce one’s dependence on, and use of, oil.
Happily, operators of tower cranes can do exactly that.
Tower cranes are electric. They can operate from the grid – if a grid supply is available at the site and if it is strong enough. Many grids, however, cannot supply the current needed for heavy and fast lifts.
Failing that tower cranes can, and frequently do, operate via a diesel generator brought onto the site. It needs to be a large and powerful one to supply enough power for the crane’s lifting phases. This, obviously, uses fuel but that fuel use can be drastically reduced, or even eliminated altogether, by using a Battery Energy Storage System (BESS) – which does what it says on the tin.
The principle is fairly simple: you put a large, rechargeable battery on your site. You tricklecharge it, either from your inadequate-for-big-lifts mains grid or from a generator – which can now be a very much smaller one since it doesn’t have to power the big lifts: the stored energy in the battery does that. All the new generator has to do is recharge the battery – and it can do that over a period of time, so requiring very much less power. Nor does it have to run all the time.
As a technology BESS is ideally suited to tower cranes. The reason is simple: tower cranes have a hugely uneven demand for power. They need a lot of it while they are actually lifting a load; but a crane lifts a load for only a tiny proportion of its time on a site.
Alex Keys is sales and marketing director at Dumarey – a UK company that makes battery energy storage systems and also, uniquely, fly-wheel-powered energy storage systems for cranes. “Most of the day the crane is not actually moving,” he says. “It is slinging, unslinging, waiting for trucks, and so on.”
In other words, tower cranes are very suitable for energy storage systems because they take large but infrequent amounts of energy, allowing plenty of time for whatever is supplying that energy to recharge the battery.
“Our batteries can charge from a small mains supply; just 32 amps is enough for it to power most tower cranes. This is due to the low average power demand,” says Keys. “If no mains supply is available and you are charging from a generator then that 32A would typically need only a 40 kVA generator which will run for just three to four hours in any 24-hour period. The battery itself can turn the generator on when it needs to charge, and off again when it’s full.
“Small generators like that are much cheaper to rent than bigger ones and require less emissions tech to comply with Stage V emissions rules. They also use less diesel per hour to run, so the net effect is significant fuel saving.
“A generator must be sized for the peak power which is only achieved very briefly as the crane accelerates the load. A large generator might use 10 litres an hour just idling on zero load. This is wasted if the crane is not moving.”
Diesel generators run extremely inefficiently on low or zero loading; Stage V generators, with all their added complexities to ensure low emissions, make the problem even worse.
“Stage V generators do not really work unless a generator is at 40% average load, and a crane cannot produce this loading,” says Keys. “We have seen a lot of sites either not complying with emission standards and getting enforcement notices, or else seeing a lot of breakdowns on their Stage V generators, or using load banks – basically banks of resistors – to produce an artificial load which drives up the diesel usage significantly.”
Which, of course, is a complete waste of fuel since that diesel is simply converted to waste heat.
COST SAVINGS
London, UK-headquartered Zenobe is another leading designer, owner, and operator of battery storage systems. Robert Long is its head of portable power.
“We have done many projects powering cranes,” he says. “Results have been very successful. When powering with a generator we can downsize the generator and increase the efficiency. We have found around a 90% reduction in fuel costs and consumption; so on a cost basis that more than pays off the higher cost of the battery.
“With regards to carbon you are also making large CO2 savings. And if you are using a battery to replace a generator entirely because you are trickle charging from a small grid supply then you have 100% fuel savings and no rental costs for the generator.
“Both of those scenarios are very compelling on an environmental and economic basis, and they have been very successful.”
Sa a BESS on-site can save a substantial amount in fuel bills. As Long points out, it also has paybacks in sustainability: less fuel means fewer carbon emissions – and on those sites that can use BESS with a low-power grid, carbon emissions can be almost zero.
“Integrating BESS into the on-site energy mix can help contractors reduce reliance on diesel and gain greater control over energy spend,” agrees Tom Adlington, sector sales manager, building services and construction at energy solutions specialist Aggreko. “Using them alongside Stage V generators running on hydrotreated vegetable oil, for example, also offers a clear route to energy-efficient emission reduction,” he adds.
SLOW TAKE-UP
Given these advantages “the technology should be taking off,” says Keys. Those in the industry, however, have been surprised at the relatively slow take-up of BESS for tower cranes.
Aggreko has produced a downloadable white paper on BESS; it is called ‘Building with BESS – How construction managers can boost site resilience using Battery Energy Storage Systems’ and is available for free download at https://bit.ly/4vxvzUV.
After listing some of the advantages of BESS – flexibility, agility, resilience, as well as green sustainability and money saving – it says this: “Despite this, their full potential is still yet to be realised by the industry; [BESS has] a range of more advanced capabilities beyond basic energy storage.”
Zenobe’s Robert Long echoes this. “Adoption of BESS for tower cranes has been slower than I had expected,” he says. Note his qualification of the statement: ‘Adoption… for tower cranes.’
Because, he explains, construction companies have been perfectly willing to hire BESS systems – indeed business is booming – but they have not been using them to their full advantage.
“From about the beginning of the year we have noticed an increase in demand for batteries in construction,” Long continues. “I have to say I expected the demand in cranes to be leading it. But, in fact, it is demand across other applications – such as welfare offices, site lighting, batching plants and applications like that. We are seeing quite a lot of deployment of batteries on those because they have a lot of requirements to be greener. Clients don’t want the generator running all day for those.
“That is useful; yet it is not as fruitful for them economically. It is a win, but not as much of a win as using BESS for a crane. You can still make savings and reduce your fuel costs on welfare but the amount of savings you can make is much higher on a tower crane.
“We know what diesel generators are like for loads with large peaks, such as tower cranes, whereas loads for welfare are more smooth and consistent, such as offices turning on lights when it gets dark, rather than a high-drain short-duration lifting load. The benefits of BESS there are still well worth making, but they are not so extreme as for cranes.”
MAXIMISING GAINS
And there are techniques for maximising the gains that BESS can bring.
Two or more cranes, for example, can be run from a single BESS. “For that, though, you might want the cranes to be physically close together,” says Long. “Power cables snaking over the site between them could be a hazard. It also might require coordinating their draws on power so that both are not lifting at the same time.”
Optimal use of BESS, though, involves not only cranes but time management and equipment management as well. This is because different bits of kit have different requirements spread over different periods of the day and night.
“Where you get best value from a battery is in powering a crane together with a more predictable load – say an office, with lights and heating, or a welfare cabin,” explains Long. “That would be an effective use of the battery and you would create a lot of value.
“Or you could pair your crane with an electric vehicle. That way you can plan your operations so that you’re always within the battery’s capability. The excavator charges at night, because that’s when it’s not being used. The crane would have no demands then because it is only used in the day. Then you have a battery that is storing and providing energy 24 hours each day. That, I think, would be a very sensible use of these batteries.
“We have a saying in Zenobē: ‘Buying a battery and using it for just one application is like buying a Swiss army knife and using it just as a spoon.’ You need to look at all the different things batteries can do at different points of the day to get the most value out of it. It is, after all, a bit of kit, which is relatively costly when you compare it to traditional technology. Make sure that you are making use of all that additional value. That is the key to making sure that you’re not decarbonising at a cost.”
When properly used, contractors can save money on decarbonization through BESS, especially as batteries have become much more available, and much cheaper, in recent years. This is partly due to better technology, partly to high volume production, and partly due to slower-thanexpected take-up elsewhere.
SECOND-LIFE BATTERIES
“We started our business using second-life batteries from buses,” explains Long. “They could no longer deliver the eight hours of continuous power that buses need but could still give reliable peak bursts of the kind that cranes require. But we wanted to grow our fleet because we had more demand, so now we use either new batteries or what we call ‘second chance’ batteries, which are electric vehicle batteries that never went to the destinations they were intended for.
“In Europe EV car sales didn’t increase at the rate they were forecast to last year so the batteries that were ordered and made for them are available as surplus. We are benefiting from that surplus because we are now powering cranes with them. The value that we add is by using our intelligence to deploy the right batteries on the right applications. So the customers always get the results they need without having to worry about the specific technology that’s being used inside the battery cabinet.”
Which is relevant because this is still an emergent technology. Early buyers into emergent technologies frequently find themselves wrongfooted as rapid developments make the original products obsolete. Thus the electric cars of five years ago have tiny ranges compared to today’s models. The reason is, simply, the progress in battery technology.
“Generator-hire companies are investing in batteries but they are rightfully being quite cautious in what is a new technology that they are not 100% comfortable with yet,” says Long.
BATTERY MANAGEMENT
The life of an expensive battery depends hugely on the precise charging regime it is subject to: running it down to flat then fully recharging it, or rapidly charging to keeping it at full all the time, are equally bad; battery management is a complex skill – and one that crane operators have neither the time, nor perhaps the inclination, to learn. They have too many other tasks on their plate.
The solution is simple: let others handle the learning curve. Instead of buying your BESS system, rent it and let the owner or manufacturer look after the charging regime and take on the risk of getting it wrong.
“The management system is built into the software of the batteries,” explains Long. “We will configure it to the individual jobsite. The main factors we consider are based on site restrictions: so, is it charging from a grid supply? If so, at what rate can it charge? What is the size of that grid supply? Can we pull 100 amps from it, or only 50? When can we charge? Are there any limitations from different hours of the day? Do we need to always charge up before 7am because they do lots of work in the morning, or is the workload evenly distributed? If the charging is from a diesel generator are there limitations on when it can run?
Some building sites now have limitations on running generators at night because local residents don’t like the noise or it could be that the site doesn’t want it to run in the day so that the people on site don’t have to have the noise and smell of a diesel generator while they’re working.
“Underlying all of this is optimising the charging strategy, and that is really quite complex. The idea is to squeeze the most value out of these battery assets and protect them so they last for a longer time. But since the crane operator is hiring them from us, that is our job, not his. We will say ‘you need to power this type of crane doing this type of operation for these kinds of hours. Here is a system that will do that.’ And we will stand behind its performance. It is our risk on that, not his. We can protect the value of our second life batteries by managing them smartly. And the crane operator gets a system that powers his cranes the way he needs.”
Crane manufacturer Liebherr has also identified this gap in the market around battery management and charging strategy. Its response has been to launched a new company, Liebherr Energy Solutions, to help customers reduce energy consumption and CO2 emissions on construction sites.
Liebherr says the new company focuses on energy storage technologies along with in-house developed software solutions, with the aim of providing energy hardware, software and service under one roof.
The company’s product portfolio currently incorporates the mobile, battery-based energy storage system, Liduro Power Port, and the browser-based Energy Planner software, for holistic planning of the power and energy requirements of a construction site in different construction phases.
“The rapidly growing energy demand on construction sites and the associated transformation of the construction industry take the topic of electrification to a new level,” explains Daniel Bachmann, managing director of Liebherr Energy Solutions. “This brings new complexity to the areas of planning, management and infrastructure. This is exactly where we come in, supporting construction site operators, planners and equipment suppliers in this transformation – efficiently, sustainably and with an eye to the future.”
The final word on BESS goes to Zenobē’s Long. He puts it simply: “If you are running a tower crane; and if you have a generator and no battery; then quite simply, you are wasting your money.” And you are pumping unnecessary carbon into the world as well.
PEAK POWER WITHOUT GRID CONNECTION
For the construction project of a new city district in Zaandam, The Netherlands, by contractor Heddes Bouw & Ontwikkeling the requested grid connection could not be delivered on time. The project would therefore have been delayed or would have had to rely solely on a diesel generator. To deliver the peak power for the tower crane lifts a large generator would have been needed, which would run inefficiently most of the time, resulting in high emissions.
Instead a BESS battery of 422 kWh capacity was used supplied by Amsterdam, Netherlandsheadquartered Greener Power Solutions. It could deliver 318kVA. The mobile battery was directly available. Delivered in a three-metre-cubed container it ensured that the construction project could start on time. The smart peak shaving capabilities of the battery ensured that a smaller diesel generator could be used – and this was supplemented by solar panels, which were mounted on the roof of the site office. This saved diesel and created a cleaner environment; it also saved also the money which a large diesel generator would have cost.
