We explain the possible solutions to grid congestion. The capacity map shows where grid congestion applies.

Most of the solutions below for grid congestion are for a wholesale electricity connection larger than 3×80 amps. These solutions can help optimize the local use of renewable energy as well as reduce the need to feed power back to the grid.

Whether there is a suitable solution for your situation depends on your location and possibilities. COMCAM can advise and support you with its extensive knowledge, experience and cooperation with grid operators. If you would like free advice, please click here.

Back to a small user connection
Using the electricity produced directly yourself
Banking of underproduction in SDE projects
Cable pooling between solar and wind projects
Exchange electricity behind the meter
Application east-west orientation in solar project
Limiting the peaks of electricity generation
Convert to another energy carrier
Energy storage behind the meter
Utilize temporary emergency lane high voltage network

Each solution is explained below including possible implications for the renewable generation subsidy (SDE).

1. Return to a small-user connection

You can reduce the capacity of your grid connection to small user connection.

This may be of interest when the capacity of your electrical system, consumption and generation, is in the neighborhood of 50 – 150 kW. Going back is possible if you take measures to limit your purchased and supplied power to a maximum of 3×80 amps.

To reduce peak consumption of electrical appliances. you can use energy-efficient variants. Think of LED bulbs for lighting or a heat pump boiler instead of a conventional electric boiler. With a small user connection, you can still supply back to the grid for the time being, even if there is grid congestion at the desired location.

See also solution application East-West orientation in solar project, limiting the peaks of electricity production and energy storage behind the meter.

Consequences for SDE subsidy
No SDE subsidy can be obtained for a small consumer connection (see conditions Rijksdienst voor Ondernemend Nederland, www.rvo.nl).

If you have an SDE decision, it will expire if you use this solution. However, you can benefit from a reduction in your energy tax when balancing and using your own sustainably generated electricity. In this way, the business case can still be positive. That makes this solution worth investigating for initiatives with peak power between 50 – 150 kW.

The balancing scheme will be maintained in its current form until Jan. 1, 2023. Starting in 2023, it will be phased out to 0 until 2031. Solar panel owners would be allowed to balance 9 percent less each year.

2. Using the electricity produced directly yourself

The electricity generated is used right behind the meter. There is no feed-in to the grid.

On an existing wholesale grid connection, you can enter into a contract with the option of feeding feed-in to the grid. The feed-in capacity is then actively limited to 0 kW (entering into a “0 kW contract”).

Electrical equipment, whether automatic or not: smart grid, are switched on when there is a surplus of locally generated electricity. This also happens when charging for energy storage charging. Thus, own use of this electricity can be maximized. Limiting the capacity of feed-in should be done according to the requirements of the regional grid operator. In this way, an installation can be put into operation even in areas of (temporary) grid congestion.

Consequences for SDE subsidy
In its SDE decisions, RVO offers the possibility of banking underproduction, provided that an installation has been put into operation on time. Commissioning can also mean that the generated electricity is initially used for own consumption and not delivered back to the grid. To make use of banking, you must meet a number of specific conditions set by RVO. For more details on the possibilities and conditions, contact RVO.

3. Banking of underproduction in SDE projects.

You can use the possibility of banking of underproduction in an SDE subsidy project.

With this, you miss out on the subsidy for renewable electricity in the first few years; in subsequent years this can be made up.

Through banking, the production and subsidy backlog accumulated in the first few years can be made up, to the extent that the production capacity of the installation allows it. This is only possible if the installation is capable of a higher annual production than stipulated in the subsidy decision. It is possible to apply for 1 extra year of banking. The underproduction can be taken every year, there is no limit to this.

Consequences for SDE subsidy
In its SDE decisions, RVO offers the possibility of banking underproduction, provided that an installation has been put into operation on time. Commissioning can also mean that the generated electricity is initially used for own consumption and not delivered back to the grid(see previous solution). To make use of banking, you must meet a number of specific conditions set by RVO. For more details on the possibilities and conditions, please contact RVO.

4. Cable pooling between solar and wind projects.

Linking a solar farm to a wind farm or vice versa, using a single (existing) connection to the public grid.

Because solar and wind usually deliver their maximum generating capacity at a different time of day, the required connection capacity of the combination of solar and wind is lower than the sum of the individual peak capacities.

Thus, more renewable generation can be realized behind one grid connection. Cable pooling is possible by one operator but also by a cooperation between different operators. If the solar farm and wind farm are operated by different parties, they can still be connected to the same grid connection. This can be done by using the ‘multiple suppliers on one connection’ option. You can arrange this by requesting an additional metering point from the grid operator. The total capacity of the connection remains the same. The joint use of the metering points may not exceed the contract value of the connection.

Read more about cable pooling variants including the possibility of “multiple suppliers on one connection” here.

Consequences for SDE subsidy
If there are multiple operators, the SDE subsidy can be maintained by using separate metering points for the solar and wind project. The electricity generation at an additional metering point is considered a direct exchange with the grid. This also makes the additional metering point suitable for the SDE scheme, which requires its own connection.

5. Exchange electricity behind the meter for large business connection

To make optimal use of the sustainably generated electricity on site and the capacity of the grid connection, electricity can be exchanged behind the meter of a wholesale connection

By building a direct cable connection to another business customer, you can deliver any surplus sustainably generated electricity directly to your neighbors. This allows you to utilize a larger portion of the electricity generated.

The direct cable connection may then only be used to transport electricity directly from the renewable generation facility to the purchasing party. You must report the construction of a direct cable connection to the Authority Consumer and Market (ACM). Also contact the grid operator beforehand to discuss the implications for the grid. An intermediate meter must be installed to measure and settle the amount of electricity supplied.

Consequences for SDE subsidy
For electricity that is self-consumed, or supplied directly to a buying party via a direct cable connection, SDE subsidy can also be obtained. The electricity production must be measured in the correct way. For existing production installations, the measurement system may have to be adapted. Please contact RFO about this to discuss the details of your situation.

6. Application east-west orientation in solar project

By applying an East-West orientation of the panels, the peak power of renewable electricity production can be limited . Thus, the capacity remains within the grid connection.

By choosing an East-West orientation instead of a South orientation, peak power per panel decreases by nearly 20%. However, production over the day is more even. As a result, annual production decreases little, about 5-7%.

The rows of solar panels can be placed right up against each other without casting shadows, which means that even more can be generated in total per square meter of roof or land than with a south-facing arrangement.

Consequences for SDE subsidy
To obtain SDE subsidy, the amount of energy produced is relevant, not the capacity. This measure therefore has no negative impact on an SDE decision.

7. Limiting the peaks of electricity production, or peak shaving or curtailment

Limiting the maximum generating capacity limits the peak capacity of renewable electricity production to stay within the capacity of the grid connection.

By limiting the peak power of a renewable generation facility using power limiting, peak shaving or curtailment, you can connect more solar panels or wind turbines to the same grid connection.

You can limit the maximum production power by undersizing the inverter of the system to the allowable power. The power of the inverter is then lower than the theoretical peak power of the solar panels or wind turbines.

You can also use separate, active power control. Since the highest production peaks occur only a few hours per year, the loss of total electricity production is very limited. For example, a 30-35% reduction in the peak power of a solar system reduces annual production by 3%. Thus, you can produce up to 50% more electricity through the same grid connection than if sized for peak power. This is because the grid connection is used more effectively: a more even load with more full-load hours.

Consequences for SDE subsidy
To obtain SDE subsidy, the amount of energy produced is relevant, not the capacity. By using this measure, a relatively small grid connection can be used to obtain a relatively large part of the SDE subsidy.

8. Convert to another energy carrier

You can maximize your own use of sustainably generated electricity by converting it to another form of energy.

Using an energy conversion system, such as a heat pump, electrolyser, boiler, locally generated electricity is converted into another form of energy. Another form of energy, such as heat, cold or hydrogen, is sometimes easier to use or store for use at a later time.

Examples: conversion of electricity to e.g. heat, cold, compressed air, hydrogen, water pressure (pumping water). This solution can be combined with energy storage behind the meter.

Consequences for SDE subsidy
When energy conversion takes place behind the meter, you can receive SDE subsidy for the sustainably generated electricity deployed behind the meter.

9. Energy storage behind the meter

Realizing energy storage behind the meter.

Energy storage, after energy conversion, can take many forms. Well-known are batteries, accumulators and heat or cold buffers.

Energy can also be stored in pressure (compressed air), gas (e.g. hydrogen), altitude energy, a flywheel, phase change materials, thermochemical storage or underground heat and cold storage (KWO/WKO).

The stored energy can then be used for one’s own energy use at a later time. The choice of type of energy storage should be tailored to the generation and use profile of the local situation. For example, thermal storage may in certain cases be cheaper and more effective than storage in the form of chemical energy (batteries or accumulators).

Implications for SDE subsidy
When energy storage takes place behind the meter to be used again later for your own use (not for feed-in to the grid), you can receive SDE subsidy for the electricity used.

10. Utilize temporary additional capacity emergency lane high voltage network

In order to temporarily free up more capacity for local generation projects, the reserve capacity of the high-voltage grid, the so-called “escape lane” of the power grid, can be used.

This can be done by applying for route exemption by the grid operator for temporary use of the reserve capacity of the high-voltage grid through mandatory redundancy to the Authority Consumer and Market (ACM).

This exemption has a maximum validity of 5 years. After this, the grid must be upgraded such that the redundant capacity can again be used as reserve capacity (normal grid operation). With the capacity freed up, the distribution system operator can then offer an accelerated feed-in opportunity to some initiatives that already have a grid connection but are not yet allowed to feed-in.

For more information on the current situation, contact your grid operator.

In the video below, grid operator Liander explains how the emergency lane can be used.

Source: Infographic 10 possible solutions to grid congestion Province of Drenthe