Storage, grid and virtual power plants
Battery storage and grid connection: four components, one system.
Solar, storage, charging infrastructure and the grid connection only show their value together. The battery is the link between them — plan the four separately and you pay for the interfaces later.
Exploded view · the components of an energy system
Battery storage
What a large battery does for your site.
Five effects that overlap in the same device. Which of them has the greatest leverage is what the load profile shows — and the sizing follows from that.
- 01 Lower demand charge The battery shaves your peak loads and so reduces the annual peak on which your demand charge is based.
- 02 Avoid or defer grid reinforcement High loads from fleet charging or motor starts are covered from the battery. Your existing connection lasts longer.
- 03 Use more of your own solar power Surpluses from the day are available during the late and night shift.
- 04 Protect production The battery stabilises your works network against voltage dips and flicker and relieves sensitive machinery.
- 05 Earn on top Free capacity is marketed through our virtual power plant on the energy markets.
Interplay
Every component changes the other three.
A larger solar array shifts the feed-in and with it the grid question. A battery changes supply and peak load. Charge points raise the peak again. The grid connection limits all of it. That is why we calculate the four together, not one after the other.
| Change | Direct effect | Consequence for the system |
|---|---|---|
| 01More generation | raises feed-in | sharpens the grid question |
| 02Add a battery | lowers supply and peak load | changes the business case of the array |
| 03Add charge points | raises the peak load | requires load management or more connection capacity |
| 04The grid connection limits | feed-in and supply | determines what is possible at all |
01 Solar
Generation that matches consumption
The size of the array comes from the load profile, not from the roof area. Orientation and layout follow the question of when in the day power is used — an east-west layout delivers a flatter but longer curve.
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Area and structure
What does the roof carry, what can be covered, where are plant and walkways?
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Orientation and tilt
South gives the higher peak, east-west the wider band.
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Shading
Rooftop plant, neighbouring buildings and trees across the day and the year.
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Self-consumption
The share that stays in the building decides the business case.
Abb. 01 Sun position and shading across the day
02 Storage and BESS
Shift energy, shave peaks
A battery has two tasks that can contradict each other: raising self-consumption and shaving peak loads. Which one dominates is decided by the operating mode — and that belongs in the design, not in commissioning.
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Sizing from the load profile
Quarter-hourly values show when the peak occurs and how long it lasts.
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Power and capacity
Two different quantities. For peak shaving, power is what counts.
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Location and fire protection
Indoors, outdoors, clearances, access, fire protection concept.
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Operating mode
Self-consumption, peak shaving, grid support — set the priorities.
Abb. 02 Battery charging and discharging across the day
03 Charging
Charge points change the site
Charge points are rarely the technical problem. The connection is: several charging at once lift the peak load noticeably — load management keeps that in check without disturbing operations.
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Usage pattern
Who charges when, how long does the vehicle stand, how much has to go back in?
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Simultaneity
They rarely all charge at full power at once — that is the lever.
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Load management
Distributes the available power dynamically instead of enlarging the connection.
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Expansion stages
Lay ducts and reserves today, add charge points later.
Abb. 03 Charge points with load management
04 Grid connection
What the grid allows determines the rest
Connection capacity, grid connection point and voltage level stand at the beginning of any serious planning. They are the one part of the project you do not decide yourself.
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Connection request
Filed formally with the grid operator, with the data from the design.
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Voltage level
Low or medium voltage — with consequences for technology and cost.
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Deadlines
The processing time belongs to the grid operator. Filing early is the only lever.
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Power quality
Harmonics and reactive power, before they show up during operation.
Abb. 04 Grid node and voltage levels
Load profile
The one file that decides everything.
The load profile in quarter-hourly values shows when energy is needed and how high the peaks are. From it follow the size of the array, the size of the battery, the operating mode and the question of whether load management is needed. Without it, every design is guesswork.
- 01 The peak sets the demand charge, not the consumption
- 02 A single outlier in the year can shape the whole bill
- 03 Only the quarter-hourly values show whether a battery reaches the peak at all
The two-route principle
Behind the meter or in front of it — the value is not created in the same place everywhere.
A battery can have two very different jobs. Which one is right is decided by the site: whether there is consumption, whether connection capacity is free, whether land lies unused.
BTM Behind the Meter
Behind the meter
Who it is for Production sites, logistics centres and business parks with consumption of their own.
- Priority lies with the site: the system feeds internal consumption first.
- The battery shaves the quarter-hourly consumption peaks and can so lower the demand charge.
- When the battery is full and production is idle, the virtual power plant markets the free capacity on the balancing or spot market.
Lower running electricity costs with no restriction on security of supply.
FTM Front of the Meter
In front of the meter
Who it is for Industrial sites with free land or unused connection capacity, plus stand-alone storage projects.
- The large battery sits directly on the medium or high voltage grid, independent of the works network.
- Automated participation in the balancing markets (FCR, aFRR).
- Using price differences on the exchange: charge when power is cheap, feed in when it is expensive.
Unused land or transformer capacity becomes a source of income — without touching the core business.
Both together are possible: during the week the system secures production loads, in quiet periods it trades on the energy market. What can be achieved depends on market prices and on the capacity that is actually free — we calculate ranges, not promises.
Principle
The grid connection is the one variable in a project that you do not decide yourself.
Everything else follows from it. That is why it comes first with us — and why the control system later decides how far it reaches.
Power quality
What happens in the network only becomes visible once you measure.
Inverters, charge points and drives change the quality of the voltage. Harmonics and reactive power lead to losses, heat and, in case of doubt, to conditions imposed by the grid operator. A measurement across a typical week shows where you stand — before the extension, not after.
Power quality as a serviceFrequent questions
What people usually ask about storage and the grid.
01 Do we need a battery at all?
The load profile decides that. A battery pays off if it either raises self-consumption markedly or reliably shaves a recurring peak. If the load profile shows neither, we say so.
02 Can we extend the system later?
Usually yes, but it is a question of the connection and of preparation. Ducts, space in the switch room and a reserve on the connection cost little today and a lot later.
03 What if the grid operator grants less capacity than planned?
Then we replan before anything is invested: smaller feed-in, curtailment, a battery or load management. That is exactly why the grid question comes before the award.
Site check
What is possible at your site?
In a thirty-minute first conversation you get an initial assessment of which combination of solar, battery storage and charging infrastructure could relieve your site. Checking and calculating come afterwards — with your load profile and the grid operator's information.
- Thirty minutes, no preparation, no obligation
- Area and grid potential: what is technically possible
- Financing options: how the project works without your budget
Helpful, but not required
- Load profile or annual consumption
- Roof drawings or an aerial photo
- Your last electricity bill
- Any plans for the site
If you have none of this, that is no obstacle. The load profile can be requested from your metering operator — we tell you how in the conversation.