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Revenue calculation

On the revenue side it is not the amount of energy generated that matters but how it is used. The same kilowatt hour of electricity has a completely different value depending on whether it is used on site or fed into the grid. The time-resolved simulation is therefore the prerequisite for a sound revenue calculation – only it shows which share of generation meets which demand and when.

Types of revenue from electricity generation

Self-consumption is usually the most valuable use: it replaces purchased electricity at the full working price including grid fees, levies and taxes. Surplus fed into the grid, by contrast, is remunerated according to the applicable regulations and is usually worth considerably less. For combined heat and power, the bonuses under the German CHP Act are added, granted at different rates for exported and for self-consumed electricity, as well as avoided grid usage fees and, where applicable, energy tax refunds. For photovoltaics, feed-in tariffs, direct marketing and models for supplying third parties have to be distinguished.

As the legal framework changes frequently, this list is a systematic overview, not legal advice. The applicable rates, deadlines and conditions have to be checked for the specific project – they depend among other things on capacity class, commissioning date, fuel and operator model.

Heat revenues

Where heat is supplied – in a local heat network or under a contracting model – revenues arise from working, standing and possibly demand prices. What counts is the heat actually delivered at the transfer point; network and storage losses reduce the sellable quantity and therefore belong in the balance. For own use, the avoided heat supply of the reference variant takes the place of the revenue.

Data basis from the simulation

EPOS-Plan provides the necessary quantities in time resolution: electricity generation from CHP and photovoltaics, of which directly used, charged into storage and fed into the grid, the remaining grid supply, the heat production per generator, operating hours, fuel input as well as residual and surplus quantities. This allows self-consumption ratio and self-sufficiency to be determined as well as the quantities to which tariffs and bonuses apply. All time series are available as CSV export for further evaluation.

Typical levers

The self-consumption share can be raised with comparatively little effort – through an east-west arrangement of the photovoltaics, through battery storage, through PV-optimised operation of the heat pump or through electricity-led operation of the CHP unit. Because each of these measures triggers investment, the benefit has to be weighed against the additional cost; the corresponding calculation is described under Economic analysis.