Greater efficiency with transparency


If the energy revolution is to succeed, it is important that Germany becomes even more energy efficient. For this reason the federal government initiated various measures in order to reduce primary energy consumption. The consumer’s contribution, however, remains largely ignored. The international consulting firm, Ecofys, has researched the effect of savings of sub-annual consumption information for tenants. The result: This measure has significant potential and is almost always commercially viable.

How much heat have I consumed when? Those who know the answer can adjust their user behaviour and handle energy more efficiently. The answer to this question gives sub-annual information on consumption in houses with multiple occupancy. This is based on the following principle: in addition to their annual heating bill tenants get monthly updates of their heat consumption and the associated costs. The results of the Ecofys study show that this measure is effective in approx. 9 of 10 cases (with an assumed reduction in consumption of 5 percent). Thus 77 PJ* of end user energy could be saved by the year 2020.

As digital technology covers about 50 per cent of houses with multiple occupancy in Germany it is already possible to implement the measure today as part of submetering. Furthermore, the federal government plans to capture heat consumption with so-called Smart Metering. Also this way, sub-annual consumer information would be possible. However, conversion to this intelligent metering technology does not become obligatory until the year 2020 and then only for households with annual power consumption of between 6,000 and 10,000 kWh. Naturally anyone can already change voluntarily today.

What is submetering?

"Submetering" is the consumer dependent metering and billing of heat consumption in apartment buildings. This means that each household only pays for the energy it has actually used.

What is Smart Metering?

"Smart Metering" is different. These are "intelligent" meters, which are primarily used to collect data of power usage digitally and in real-time.

Tenants already benefit from small savings

The consulting firm Ecofys was interested foremost on whether usage information during the year was of financial benefit for the consumer or whether it would additionally burden the household budget. For this, reference buildings from seven construction eras (old buildings before 1978 to new builds) with four energy providers each (natural gas, oil, district heating and electricity) were compared within the framework of a profitability study. ista metering data provided the basis for respective energy usage as well as the associated costs.

“Sub-annual consumprion information is already of financial benefit for a wide majority, with savings of 5 percent.”

This shows: A saving of 5 percent is already of financial benefit for a wide majority when based on sub-annual consumption information. With estimated costs of 30 euros per year and apartment, this measure is financially advantageous or at least cost neutral for 87 per cent of tenants. This means end energy savings of 77 PJ* by 2020, which is economically feasible for the consumer. When costs lower to 20 euros per year, almost all tenants profit from the usage information and 85 PJ* of end energy can be saved without any on costs.

The economic viability of sub-annual consumption information with an estimated saving of 5 %

Expected costs are affected significantly more when the measure saves merely 3 percent of energy. A financial benefit is rarely achieved when households pay 30 euros per year. The extra costs of up to 10 euros annually are, however, more manageable for the consumer. The majority of tenants (82 percent) benefit from this measure when only 20 euros per year and residential unit are invested.

Fast implementation with submetering

How can the immense saving potential of sub-annual consumption information be realised as quickly as possible? Which route – submetering or Smart Metering – is the more effective? To answer these questions, Ecofys calculated the end user energy savings for room heating and hot water based on submetering as well as Smart Metering up to 2030. The basic assumption was a reduction of consumption at 5 percent. At the same time, market penetration by relevant technologies in the course of the next few years was taken into consideration.

Here submetering facilitates immediate energy savings, as the necessary digital technology is currently already established in about 50 per cent of houses with multiple occupancy in Germany. Energy consumption in Germany could be lowered by 20 PJ* by 2017. Moreover, technology is establishing itself more and more on the market. Therefore possible savings through submetering alone add up to 89 PJ* by the year 2020.

“An increase in the transparency of consumption allows tenants to actively reduce end energy, and thus contribute to the success of the energy turnaround, and allows owners to enhance the attractiveness of their properties.”

In contrast, the rollout for Smart Metering does not start until 2020. Sub-annual consumption information through both routes can therefore only be implemented from that date, which is the reason for Ecofys setting the timescale for the investigation to 2030. In 2030, energy savings of 3 PJ* are predicted for single-family dwellings, achieved via Smart Metering alone. 12 PJ* would be added to this in houses with multiple occupancy, which could be achieved through either submetering or Smart Metering. Submetering has the greatest savings potential with 19 PJ*. A total of 34 PJ* of end energy would be saved in the year 2030 with this measure.

The potential of consumption transparency

An increase in the transparency of consumption allows tenants to actively reduce end energy, and thus contribute to the success of the energy turnaround, and allows owners to enhance the attractiveness of their properties. Sub-annual consumption informationalmost always already pays off for tenants with small savings of 5 percent. Furthermore, this can be implemented immediately within the framework of submetering. Even after the introduction of Smart Metering in 2020, the greater ratio of end energy savings would be due to this measure. Submetering can make a significant contribution towards utilising the considerable potential of intrayear usage information quickly and comprehensively.

Moreover, other studies such as the pilot scheme “Saving money through clever heating”, which is currently being implemented by the German energy agency, emphasise the far greater saving potential of sub-annual consumption information. Here, informed participants were able to reduce their heat consumption by an average of about 9 percent. Therefore, these measures could prove to be even more effective in practice.

*3.6 Petajoule are equivalent to 1,000,000 MWh

picture credits: ista, grasundsterne