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Site Power ROI Calculator
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BESS vs Diesel Generator
Cost Comparison

Adjust your project parameters below to instantly see whether a Battery Energy Storage System or a diesel generator makes financial and environmental sense.

Project Parameters

£390/wk
100 kVA · 80 kW ÷ 0.8 pf
Indicative UK market rate — actual quotes vary
Avg Demand
0 kW
Peak Demand
0 kW
Gen Spec
—
35.0 L/hr
500 kVA gen · 35.0 L/hr (part-load idle burn)
Generator burns fuel based on its rated size, not actual load — idle burn is the biggest cost on crane sites
How we calculate this

Generator Auto-Spec

Required kVA = peak_demand_kW ÷ 0.8 (power factor) Fuel consumption = generator_kVA × 0.07 L/hr

A 500kVA generator burns ~35 L/hr at part-load — the same whether the crane is lifting or idle. This is the key cost driver on crane sites that the BESS eliminates entirely.

Generator Total Cost

Hire = duration × gen_rate Fuel = duration × hours_per_week × fuel_consumption × diesel_price

BESS Total Cost

Hire = duration × bess_rate Charging ≈ £0.28/kWh × avg_demand_kW × hours_per_week × duration

CO₂ Avoided

Diesel CO₂ = fuel_consumption × hours_per_week × duration × 2.68 kgCO₂/litre Grid CO₂ = avg_demand_kW × hours_per_week × duration × grid_intensity Net CO₂ avoided = Diesel CO₂ − Grid CO₂

Diesel emission factor: 2.68 kgCO₂ per litre burned (BEIS 2023). Grid carbon intensity: UK average 0.233 kgCO₂/kWh (National Grid ESO, 2024). Charging cost assumes £0.28/kWh grid rate. These are indicative estimates; actual costs vary by site, contract, and usage patterns.

BESS vs Generator — project saving
£0
0% cheaper with BESS
Jule. Intelligence

Putting your numbers into perspective

🌱 The CO₂ you'd avoid is equivalent to...
—
✈️ return flights
London → New York
—
🌳 trees growing
for a full year
—
🚗 miles not driven
in an average car
—
🎈 party balloons
filled with CO₂
💰 Your savings could buy...
—
🍺 pints of beer
at a UK pub
—
📅 days of average
UK salary
—
⚽ Premier League
season tickets
⛽ Generator Total
Equipment hire
£0
Fuel cost
£0
Total cost
£0
🔋 BESS Total
Equipment hire
£0
Charging cost
£0
Total cost
£0

Cost Comparison

⛽ Generator £0
🔋 BESS £0

🌱 Environmental Impact

Diesel CO₂ emitted
0.0 t
BESS grid CO₂
0.0 t
Net CO₂ avoided
0.0 t CO₂
equivalent to 0 cars off the road for a year
✅ BESS saves you £0 on this project
Switch to BESS and eliminate £0 in fuel costs.
💡 Reduce your carbon footprint by 0.0 tonnes CO₂
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