Tons of TNT to Megawatt Hour

One ton of TNT releases 4.184 GJ — roughly the energy of 120 liters of petrol or the electricity an average US home uses in 1.2 days. In blast terms, one ton of TNT in open air produces lethal overpressure within about 15–20 meters and can shatter windows at 100+ meters. The MOAB bomb (11 tons TNT) flattened structures across a 150-meter radius.

They differ by factors of 1,000: 1 kiloton = 1,000 tons, 1 megaton = 1,000,000 tons. Conventional bombs are rated in tons (the MOAB is 11 tons). Tactical nuclear weapons are rated in kilotons (Hiroshima was ~15 kt). Strategic thermonuclear warheads are rated in megatons (modern US warheads are 0.3–0.475 Mt). The scale spans nine orders of magnitude.

The 2020 Beirut explosion was caused by 2,750 tonnes of ammonium nitrate and was estimated at roughly 500–1,100 tons of TNT equivalent. For comparison, the Oklahoma City bombing (1995) was about 2 tons TNT equivalent, and the Halifax explosion (1917) was roughly 2,900 tons. Beirut ranked among the largest non-nuclear explosions in history.

Small meteor airbursts are rated in tons or kilotons of TNT. The 2013 Chelyabinsk meteor released about 440,000 tons (440 kt) — roughly 30 times the Hiroshima bomb. The Tunguska event (1908) is estimated at 3–15 megatons. The Chicxulub asteroid that ended the dinosaurs released roughly 100 trillion tons (100 million megatons) of TNT equivalent energy.

The largest planned non-nuclear explosion was the British demolition of Heligoland fortifications in 1947, using 6,700 tons of TNT equivalent. The largest accidental explosion was the Halifax harbour disaster (1917) at roughly 2,900 tons. The largest conventional bomb, the US GBU-43/B MOAB, yields about 11 tons — tiny compared to accidental industrial blasts.

MWh is the natural unit for grid-scale transactions because power plants and large industrial loads operate in the megawatt range. Quoting in kWh would produce unwieldy numbers — a 1 GW nuclear plant generates 24,000 MWh/day, not 24,000,000 kWh. Spot markets like the US PJM or European EPEX quote prices in $/MWh or €/MWh, typically $20–$80/MWh in normal conditions.

One MWh powers the average US home for about 1.1 months (since the average is 886 kWh/month). In Europe, where consumption is lower (~300 kWh/month), one MWh can cover about 3.3 months. A single MWh is also enough energy to drive an electric car about 5,000–6,000 km, or to run an industrial air compressor for roughly 4 hours.

US wholesale prices typically range from $20 to $80/MWh depending on region, time of day, and fuel costs. European prices are generally higher at €50–€150/MWh. During extreme events — heat waves, supply shortages — prices can spike above $1,000/MWh for brief periods. Negative prices (below $0/MWh) also occur when wind or solar oversupply the grid.

A modern onshore 3 MW turbine at 35% capacity factor produces about 9,200 MWh/year. A large offshore 15 MW turbine at 50% capacity factor generates roughly 65,700 MWh/year. Capacity factor — the percentage of theoretical maximum output actually achieved — varies with wind resource, turbine technology, and maintenance downtime.

Current lithium-ion battery costs (~$150–250/kWh) make 4-hour systems economical for peak shaving and solar time-shifting, but 24-hour storage would cost 6× more with diminishing returns. Grids instead layer solutions: batteries handle the evening peak (4 h), gas turbines cover overnight baseload, and pumped hydro or compressed air provide longer-duration backup. Iron-air and flow batteries are emerging for 100+ hour storage at lower cost per kWh, potentially closing the gap by the 2030s.