Vocabulary
Power grid: power plants, power connections, cities
Market: bid/ask-based market for trading resources and power
Order: bid/ask order to buy/sell resources or power
Merit order: a special kind of order created every tick for every power plant to resolve grid balancing and spot price
Spot price: the highest price offered by merit orders, which were used to satisfy demand
Power Grid
Every city has its own power demand based on its population and percentage of people connected to power. Power demand is calculated for every tick.
Every power plant in city creates merit orders as candidates to satisfy power demand. Some power plants create more than one merit order to create different offers based on produced quantity.
Example:
Power demand is 10 MWh.
Solar power plant creates merit order for 4MWh@$150
Result: Solar power plant will produce 4MWh if weather is sunny and sell energy on market at $150 per MWh which is also spot price for this city for current tick. City is missing 6MWh so it will reduce its population and demand in future ticks.
Example2:
Power demand is 10 MWh.
Solar power plant creates merit order for 4MWh@$150
Coal power plant creates merit order for 8MWh@$230
Gas plant creates merit order for 8MWh@$240
Result: Solar power plant will produce 4MWh, coal power plant will produce 6 MWh. Tick algorithm will favor offer from Solar power plant because its cheaper. Spot price will by $230 because merit order from coal power plant was at least partially used so maximum price from used orders is $230.
Solar plant owner will receive 4 * 230 = $920
Coal plant owner will receive 6 * 230 = $1380 and also damage for causing overload (2MWh)
Gas plant will receive only damage for causing overload (8MWh)
City will grow in future ticks because demand was satisfied.
DEV note: Merit orders are created automatically for each power plant. We are planning to implement market feature which will enable players to override preset merit orders.
Market
Market orders are different from merit orders. You can offer “unlimited“(limited by market credit) quantity of power on market without having any power plants. You will immediately receive money from market if someone trades against your offer. In next tick you should deliver this amount of power or it will be automatically bought from market at spot price.
Example:
Player1 creates market order 100MWh@$200 without having any power plant
Player2 accepts this offer.
During next tick: Spot price ($300 for example ) will be calculated based on merit orders and demand (see previous chapter). Player1 has no power so it will be purchased on market.
Result: Player1 received $200 000 from Player 2 but paid $300 000 for power from market so loss is $100 000