Solar Self-Consumption
Maximize Solar Self-Consumption: Use More of Your Own PV Power
Maximizing self-consumption means a building uses as much of its own solar power as possible on site, instead of feeding it into the grid at a low price and buying expensive grid electricity. Ventilation, chillers, and heat pumps run specifically when the PV system is generating power, turning the building itself into thermal storage. The self-consumption rate rises, grid consumption falls, and the PV system pays for itself faster, often without the need for battery storage.
Solar System Installed, but Your Electricity Bill Is Still High?
A PV system generates power when the sun shines, not automatically when power is needed. If this power isn't used on site, the only option is usually to feed it into the grid, but feed-in tariffs keep falling and in many markets no longer apply to large systems. Increasing the self-consumption rate therefore becomes the key lever, because:
Expensive grid electricity and falling feed-in tariffs extend the payback period of a PV investment.
Battery storage seems like the obvious solution but again requires a high investment.
The alternative is demand side management: running existing electrical equipment specifically when solar power is available.
What Is the Self-Consumption Rate?
The self-consumption rate describes what percentage of the solar power generated on site is used directly in the building instead of being fed into the public grid. A rate of 60 percent means 40 percent of the PV power flows unused into the grid. The higher the self-consumption rate, the better the economics of the PV system, because self-generated power replaces expensive grid electricity, while feed-in tariffs play an ever smaller economic role.
Benefits of a Higher Self-Consumption Rate
More Self-Generated Power, Less Grid Electricity
By aligning ventilation systems, chillers, and heat pumps intelligently with solar generation, additional PV power can be used directly in the building. Depending on the existing and controllable systems, the optimization potential is around 10 to 20 percent of annual PV yield.
Better PV Economics
More self-consumed power means less grid electricity. This improves the profitability of the PV investment and shortens its payback period without additional hardware.
Lower Investment in Battery Storage
By using the building itself as thermal energy storage, for example through pre-cooling during sunny hours, the need for additional battery capacity can be reduced.
Increase Solar Self-Consumption in Two Steps
A higher self-consumption rate doesn't come from a single measure. It always depends on the interplay between the PV system, building systems, and consumption.
01
Connect PV Generation and Building Systems
With aedifion.dynamics, your systems are connected around a common goal. The existing systems of your building automation are used to control heating, ventilation, and air conditioning optimally. Either the PV system is connected as a data source that the other systems align with, or inverters and battery storage are integrated as active elements so that optimized operating parameters such as time-dependent power limits can be set for them directly.
02
Align Loads Flexibly With Solar Power
As soon as the PV system generates power, aedifion.dynamics coordinates the systems so that as much power as possible is consumed directly in the building. The building itself becomes thermal energy storage. All settings stay within defined limits for temperature, air quality, and occupancy times so that occupant comfort is not affected.
“aedifion.dynamics acts like a control system that keeps an eye on all building components around the clock: as soon as solar generation rises, the heat pump, chiller, and ventilation system increase their power demand. This way, the building uses as much solar power as possible directly and stores surplus energy thermally, as heat or cold, or in existing battery storage for later.”
Dr.-Ing. Thomas Schreiber | Teamlead Engineering & Research
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Which Buildings Benefit Most From Higher Self-Consumption
Higher self-consumption delivers the greatest benefit in buildings that are used intensively during the day, in other words during peak sunshine hours: commercial properties, office buildings, shopping centers, hotels, healthcare facilities, and logistics properties.
A potential check is particularly worthwhile if
- a PV system is in place and the self-consumption rate is below 70 percent.
- the building has controllable ventilation systems, chillers, or heat pumps.
- setpoints can be written via the building automation down to room level.
- the energy charge for grid electricity is significant.
Optimization potential can exist even if these conditions are only partly met. The basic requirement, however, is that the relevant data points that influence the output of ventilation systems, heat pumps, or chillers can be written via open protocols (e.g., BACnet, Modbus). Existing or planned battery storage can be an advantage but is not a prerequisite.
Increasing Self-Consumption: What Is Realistic?
The optimization potential depends on the existing systems. In a building with a heat pump and chiller where heat and cold distribution can be fully controlled, the additional self-consumption potential is typically around 20 percent of annual PV yield. If only the chiller and ventilation system can be controlled, the additional potential is around 10 percent of annual PV yield.
Frequently Asked Questions
Self-consumption can be increased by aligning flexible loads specifically with the times of solar generation. Heat pumps, chillers, and ventilation systems can be operated within defined limits so that more self-generated power is used directly in the building. How large the potential is depends on the existing and controllable building systems.
There is no universal target. The self-consumption rate depends, among other things, on the size of the PV system, the consumption profile, and the flexible loads available. Under suitable conditions, the self-consumption rate can increase, for example, from 60 to as much as 70 percent.
It depends on the individual case. If controllable thermal systems such as heat pumps, chillers, or ventilation are in place, the building control system can take over a significant part of the storage task. A small battery can be a useful addition; a large one is often unnecessary. Based on existing building data, aedifion can show how much of the storage need can already be covered through building operations.
Maximizing self-consumption targets the amount of energy (kWh): self-generated solar power should be used in the building as completely as possible. Peak shaving targets power (kW): demand peaks are capped to lower demand charges. The two goals can complement each other.
Yes. Dynamic electricity tariffs link the energy price per kWh to wholesale electricity prices. Using them requires a smart meter. In addition to using your own solar power, flexible loads can then be shifted specifically to low-price hours. What is possible in practice depends on the existing systems, the building automation, and your supply contract.
Make the Most of Your Own Solar Power
Find out how much potential lies in your PV system and building operations. We analyze your technical requirements and show you which loads are suitable for increasing self-consumption.
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