What factors are important in judging how helpful an energy resource is to us?

Supply. Energy from nuclear, coal, gas, oil, and renewable sources reacts quickly in response to the available supply (or lack thereof). This is a key contributing factor to price fluctuations, which can occur on an hourly basis.

Demand. Demand for heating, cooling, light, and processes varies in response to demand in terms of economic, technological, and efficiency measures.

Gas Storage. This is a term for energy “inventory” (since you can’t store electricity), i.e. the difference between supply and demand. Gas injections and withdrawals are announced weekly, and prices adjust accordingly.

Weather Forecasts. The predicted weather forecast, as well as actual weather events, are important considerations, affecting spot market prices and short-term contracts. Whether the forecast becomes reality is less critical to longer-term prices.

Generation Changes. While seemingly more localized, these changes can have a broad effect on the markets.

Nuclear. Retirement of older plants as they require re-licensing can cause fluctuations.
Coal. Coal plant conversions to natural gas to avoid scrubbing-technology costs can also cause fluctuations.

Transport. Across the U.S. there are severe constraints in gas pipeline and electrical transmission capacity, which take time and investment to reverse. With the difficulty of transportation, prices rise.

Global Markets. Despite the massive growth in shale gas production, major changes in global oil supplies can affect U.S. domestic energy costs.

Imports and Exports. Global oil and gas prices determine relative profits suppliers can make selling fuels domestically or overseas. All energy prices are connected to some degree.

Government Regulation. Federal (FERC) and state (PUCs) regulations can change both supply and demand costs quickly and significantly, which, as noted above, affects the cost of energy.

Financial Speculation. Like most other traded commodities, energy prices can be affected significantly by financial speculation, which is the least transparent factor of all. If a market doesn’t seem to be following the direction indicated by supply or demand-related factors, the cause is almost always financial speculation, which is largely invisible and causes unexpected movements.