Five years without electricity bills: utopia or reality?

A house with no energy costs sounds like an impossible dream. But one electricity provider promises exactly that. What's behind it? And what's the catch?

A home that doesn't have any electricity costs – that sounds unrealistic and tempting at the same time. The electricity provider Octopus Energy now wants to make this scenario a reality. With the zero energy cost house concept, the company promises its customers five years of living without electricity costs.

How exactly does this concept work? What do interested parties need to consider?

The concept of the zero-energy-cost house is not new. It has been discussed in the industry for a long time. However, its implementation usually involves high investments. In order for the property to not incur any energy costs, it must be equipped with a powerful photovoltaic system, an efficient heat pump and sufficient battery storage.

All of these systems then work together to cover the energy needs of the house. In addition, the property must be insulated with highly insulating building materials and equipped with the latest building technology so that no (heating) energy is lost. The idea behind this is that a house produces just as much energy over the course of a year as it consumes.

A crucial factor in making the calculation work is the photovoltaic system (PV system) on the roof. It generates solar power, which is either used directly or temporarily stored in the solar power storage unit. This means that there is enough energy available even on days with little sun. If the solar power storage unit is empty, the battery can also be charged from the grid. The catch: the PV system has to be very powerful, and the power storage unit has to be very large and durable.

A heat pump, powered by solar energy, also heats or cools the house efficiently. Smart control systems optimize energy consumption and ensure that resources are used optimally. If just one of the systems causes problems, the math doesn't add up.

To benefit from Octopus Energy’s offer, those wishing to build must meet the following conditions:

• The house needs to be rebuilt.
• The location of the house must be chosen so that sufficient solar radiation is ensured.
• Certain construction standards must be met (at least KfW 50).
• The planning and construction is carried out in cooperation with accredited construction partners.
• Octopus Energy takes full responsibility for the intelligent control of the technical systems using its own technology platform.
• Electricity is purchased exclusively via Octopus Energy and consumption is transmitted to the provider via smart meter

The house builders turn to a construction company that works with Octopus Energy. Together they then design and build the house according to the specifications to achieve the zero energy cost target. This means that a heat pump, a photovoltaic system and a battery storage system must be present. According to Octopus Energy, a wall box for an electric car is also possible in the concept.

The builder covers all costs. With the Zero Bill House, as the zero energy cost house project is called by the provider in Great Britain, Octopus Energy guarantees that there will be no energy costs for the residents, provided they adhere to the above-mentioned requirements. The energy supplier achieves this by concluding an electricity contract with the customer with a dynamic electricity tariff and also using the company's internal control tool (Kraken software) to control the additional electricity used by the residents from the public grid. You can find out all the advantages and disadvantages of the dynamic electricity tariff here. Through arbitrage trading on the electricity market, the energy costs then amount to zero euros over the year.

There is currently only one zero-energy-cost house in Berlin. It will be offered on Immoscout24 in the coming days. Interested parties can then apply for it, as is usual with a property. However, only as a tenant.

If the project is successful, more zero-bill houses will be built – but here the builders will determine the appearance and equipment according to the specifications. Catalog houses are not yet planned in this country, according to Octopus Energy.