Megawatt Hour to Grams of TNT

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.

By convention, exactly 4,184 joules — the same as one thermochemical kilocalorie. Real TNT detonation yields vary by about ±2% depending on purity and confinement, but the defined value provides a fixed reference point. This makes the gram of TNT a convenient bridge between chemistry (calories) and explosive engineering.

TNT (trinitrotoluene) became the reference explosive because it is chemically stable, safe to handle, and was massively produced during both World Wars. Its consistent detonation properties made it a natural benchmark. Other explosives are rated by their "TNT equivalent" — for example, C-4 is about 1.34× TNT and ANFO is about 0.74× TNT.

A standard US consumer firecracker contains about 0.5–1 gram of TNT equivalent in flash powder. An M-80 (now illegal for consumer sale) contained roughly 3 g of TNT equivalent. Cherry bombs were about 1.5 g. Commercially sold fireworks are regulated by the CPSC to contain no more than 50 mg of flash powder per report charge.

A US M67 fragmentation grenade contains about 180 g of Composition B explosive, which has a TNT equivalence of about 1.33×, giving roughly 240 grams of TNT equivalent. The lethal radius is about 5 meters, with a casualty-producing radius of 15 meters. The fragmentation — not the blast energy alone — is the primary wounding mechanism.

One gram of TNT releases exactly 1 thermochemical kilocalorie (1 kcal = 4,184 J) by definition. This means a dietary Calorie (nutritional kcal) contains the same energy as detonating one gram of TNT. A 2,000-Calorie daily diet is energetically equivalent to 2 kg of TNT — though your body releases that energy over 24 hours, not in microseconds.