Is there a source for national electricity prices for current and preceding years/ months for individual or grouped countries? I would like them in a standardized measure but national currencies is good enough and just adds an additional conversion step.
The European Energy Exchange (EEX) is a marketplace for European energy (electricity), both futures and spot prices (although most trading is done either with brokers or as OTC). From your question it sounds like you are looking for spot auction prices, which are traded the day before delivery and have hourly resolution. That means each hour of the day has one settled price and volume. Multiple markets/countries have individual prices. The markets trading on EPEX Germany/Austria, Switzerland, France, UK, Netherlands, Belgium. EPEX prices are available from the parent company, EEX. Unfortunately, only individual days are available, so you can either copy/paste one by one, or scrape the HTML (hint: there is a json file somewhere in the source code)