Possibilities of premises and apartment buildings to offer flexibility for electricity markets and local power balancing are studied in Building level intelligence pilot. Researchers from VTT and Aalto University will give us a peek to the preliminary findings of the pilot.
To be able to answer to the question if buildings can offer flexibility and in what extent, we first need to get access to the data of existing measurements and databases, conduct audits together with the persons in charge of various systems, install additional measurements for promising systems to understand the division of energy consumption, power dynamics and the operation of control systems as well as the role of local production and energy recovery options.
– We had to assess which electrical loads would be worth of more detailed analysis and large enough for meaningful control trials as part of the experiments paving the way towards markets and local solutions, says pilot leader Mikko Hongisto, Senior Scientist at VTT.
When we try to design control changes for heating, cooling and air conditioning systems, it is extremely important to foresee and measure how the conditions in the buildings will be affected. The object is to minimize negative impacts on workers and buildings using feedback loops and sensor networks.
– We intend to start from carefully selected transients to improve the evolving control model and understand limiting factors.
– Globally, there has been a few similar pilots, but as Nordic energy market is a global forerunner regarding energy data and markets, we are doing pioneer work together with our company partners here at Smart Otaniemi, postdoctoral researcher Toni Tukia from Aalto University says.
Clustering the energy consumption profiles of buildings
– First, we started with analysing historical energy consumption data of office, university and residential buildings. We got data of half of the buildings in the Otaniemi area straight from property owners, Toni Tukia tells. We clustered the buildings based on their consumption profiles and tried to find out, which buildings are closest to the average consumption profile of each cluster, Tukia explains.
– The idea is then to make more detailed measurements in these average buildings in order to understand how much energy for example heating, cooling and ventilation uses at certain times. This is important data regarding flexibility potential. Developing energy metering of sub-systems is one of the goals in the pilot, Toni Tukia says.
At Otaniemi in general, the electricity consumption profiles of buildings are quite stable throughout the year.
– Consumption profiles of office and residential buildings differ of course, and if we think from the solar power opportunities perspective, they nicely complement each other. Especially the energy consumption of cooling, heating and ventilation is quite predictable, so it is easy to estimate their maximum flexibility potential in the future, Toni Tukia confirms.
– For example, the preliminary results in the assessed buildings suggest that the controllable loads account for around 40–50% of the total electricity consumption. However, it is unclear whether this potential can be realised in practice to meet requirements of users and various electricity market segments, Mikko Hongisto adds. The prerequisite for controls is the acceptance of all stakeholders of these buildings.
New solutions enabling flexibility needed
– One of the most surprising findings has been that in some laboratory buildings the total electricity consumption is peaking during hot seasons. The electricity consumption of cooling in the laboratory buildings is also substantial almost throughout the year and, while the condenser heat is significant, it is not yet possible to utilize it in the heating systems, Mikko Hongisto says.
– For that reason, we try to solve, how to control a large chiller unit in practice aiming to interlink its operation to the frequency containment reserve -market without compromising local conditions in the building. In addition to this, solar power opportunities to supply this kind of chiller units exist due to a good correlation of consumption and yield. As all office buildings have cooling systems, there’s also possibility to utilize both of them for combined load control and balancing purposes.
– For companies, there is a clear message that solutions for these flexibility needs are worth developing. They are already needed in Finland, and even more so globally.
Over production of solar energy is rarely a problem
Studying solar power potential at building level has been one important aspect in the pilot. Solar power production opportunities differ in various buildings, but it seems, that up to 20% of the annual electricity usage in the area could be produced by solar panels. – We have found out that equipment at rooftops significantly restricts the production of solar panels because of shading.
– One conclusion is that it is quite difficult to create over production situations in a majority of office buildings, even though we would install maximum solar production capacity on buildings. Also wall mounted installations should be considered as well as next generation solar hybrids with batteries if uninterruptible power supply is needed, Mikko Hongisto says.
Toni Tukia adds that, nowadays, the amount of installed solar power capacity is typically optimised so that the production capacity doesn’t exceed the electricity consumption of the building. However, from the perspective of CO2 emission reductions, it would be useful to install more solar power than the building consumes. Excess energy can be used in nearby buildings, for example, within the local energy community. The problem is that we need ways to clearly show that electricity has come from nearby buildings. In the future, the distribution system operators could provide different fees for local power sharing in contrast to buying power from centralised power plants over the whole power transmission network.
Control system of large chiller unit and opportunities to utilize solar power is investigated in Building level intelligence pilot.
More results can be expected during spring 2020
The next step is to connect most promising controllable sub-systems to a larger pool of “controllables”, execute the required trial experiments to understand technical and perceived tolerances and conduct pre-qualification tests and in the end: bring flexibilities as a virtual power plant to suitable electricity market segments.
– The pathway is long and a lot work and co-operation between various experts and organizations will still be needed, and we should be able to finalise the pilot during spring 2020, Mikko Hongisto tells.
One other thing we have noticed but are not able to tackle in our current work-package is that in the Otaniemi area there is a huge potential of wasted condenser heat waiting systemic solutions and new energy recovery pilots, Mikko Hongisto says.
So far, we have not been able to utilise these potentials, since the cost-components of heat and electricity are typically distributed between property owner and tenant. Logical background policy is that the benefits and costs of flexibility measures will should be allocated to the payer of the electrical energy bill. For the time being, strong financial incentives are lacking to introduce energy efficient heat pumps for heat recovery in this kind of multi-organizational situation – advanced sub-system metering is needed. Also new benefit sharing models should be created, to fully capture the energy efficiency and flexibility potentials of buildings, Hongisto summarises.
Building level intelligence pilot’s page
Mikko Hongisto, Senior Scientist, VTT, tel. +358 40 720 1250, firstname.lastname@example.org
Toni Tukia, Postdoctoral Researcher, Aalto University, tel. +358 40 066 3836, email@example.com