IVL Swedish Environmental Research Institute

Verktyget Tidstegen kan användas för att analysera klimatpåverkan vid val av olika energiåtgärder. Resultaten från verktyget kan med fördel användas som ett komplement till andra beslutsunderlag (ekonomi och innemiljö med mera) när ett bygg- eller fastighetsföretag står inför beslut att genomföra en investering i nybyggnation eller i ändring av en befintlig byggnad. I rapporten beskrivs resultat från fyra olika pilotprojekt som har använt verktyget för att analysera klimatpåverkan av olika energiåtgärder i byggnader. Pilotprojekten har även bidragit till utvecklingen av verktyget genom regelbunden återkoppling. Pilotprojekten har genomförts i tre olika fjärrvärmenät (Linköping, Stockholm Nordvästra samt Stockholm Södra och Centrala). Ett av pilotprojekten har även inkluderat energilösningar med fjärrkyla och två pilotprojekt har omfattat solcellslösningar. Beräkningarna i verktyget Tidstegen bygger på så kallad konsekvensanalys, som innebär att effekterna av en förändrad energianvändning analyseras. Det är alltså bara de anläggningar i energisystemet (el, fjärrvärme, fjärrkyla) som påverkas av den förändrade energianvändningen som ingår i konsekvensanalysen. Verktygets beräkningar bygger på metodik som utvecklats av IVL i flera tidigare forskningsprojekt i samarbete med representanter från bygg-, fastighets- och energibranschen.

Within the Domsjö Biorefinery cluster in Örnsköldsvik, all the industries are cooperating regarding energy. The cluster consists of one wood pulp production facility, two bio-chemical facilities and one energy facility.

In this study, we have analysed how efficient the steam is used within the industries. Are steam of right pressure and temperature used for the right purposes? To what extent could steam be replaced by district heating? And, how big is the potential to use simultaneous heat and cold demand for energy integration? The method for energy analysis was “pinch analysis”.

It is found that steam of 7 bar(g) and 170 °C is used to supply a major part of the heat demand, sometimes even heat demands of low temperatures. Such demands would be more efficient to supply by district heating. Alternatively, a new utility with temperatures 40/120 °C could be introduced, either within the total site, or only within the biggest of the industries. The practical heat recovery potential is about 15 MW for the total site, and about 10 MW at the biggest of the industries.

For all alternatives, steam capacity is released, which for example could be used for increased industrial production without investments in new steam boilers. Alternatively, the released capacity could be used to completely (or partially) offset the steam requirements of a new process plant at the Domsjö site.

Within the Domsjö Biorefinery cluster in Örnsköldsvik, all the industries are cooperating regarding energy. The cluster consists of one wood pulp production facility, two bio-chemical facilities and one energy facility.

In this study, we have analysed how efficient the steam is used within the industries. Are steam of right pressure and temperature used for the right purposes? To what extent could steam be replaced by district heating? And, how big is the potential to use simultaneous heat and cold demand for energy integration? The method for energy analysis was “pinch analysis”.

It is found that steam of 7 bar(g) and 170 °C is used to supply a major part of the heat demand, sometimes even heat demands of low temperatures. Such demands would be more efficient to supply by district heating. Alternatively, a new utility with temperatures 40/120 °C could be introduced, either within the total site, or only within the biggest of the industries. The practical heat recovery potential is about 15 MW for the total site, and about 10 MW at the biggest of the industries.

For all alternatives, steam capacity is released, which for example could be used for increased industrial production without investments in new steam boilers. Alternatively, the released capacity could be used to completely (or partially) offset the steam requirements of a new process plant at the Domsjö site.

Denna rapport avhandlar energieffektiviseringspotentialen för ett bostadshus av Miljonprogramsstandard genom fönsterrenovering enligt företaget Grundels metod. Potentialen har uppskattats med avseende på en förbättring av klimatskalets isolerförmåga genom energisimuleringar av ett referenshus utförda i IDA ICE. Fönsterrenovering enligt Grundels metod uppskattades resultera i en minskning av byggnadens energibehov med ungefär 14 % för det aktuella referenshuset. Renoveringen uppskattades också leda till en minskning av byggnadens U-medelvärde, de genomsnittliga energiförlusterna genom ledning fördelade på byggnadens omslutande area, med ungefär 20 %.

The energy use of buildings affects the entire energy system. Choosing climate-friendly energy solutions and renovation strategies in the building stock is thus an important part of the transition to a more sustainable energy system. The construction industry and the real-estate sector have been lacking practical tools to assess the climate implications of different energy solutions in buildings, accounting for the interaction with the energy system.

We developed a tool for calculating the climate impact of a change in a new or rebuilt building, taking into account the interaction between the building and the overall energy system, regarding greenhouse gas emissions. The tool is called Tidstegen and is based on a methodology that has been developed in several research projects. The methodology takes into account the point in time when the building uses and/or produces electricity, heat and cooling, and also the development of the energy systems over time. It analyzes the consequences of changes. This is usually referred to as an environmental assessment from the decision perspective or consequential assessment. It is an established approach in life cycle assessment. The calculations include consequences that occur in the local district heating system and also in the North European electricity system.

The Tidstegen tool allows for making more informed decisions when renovating and building new properties. It can be used by, e.g., property owners, consultants, municipalities or builders as one of several decision-support tools when making decisions on energy efficiency measures or investments to produce renewable electricity, heating or cooling at, on, or in the building. In the tool Tidstegen you compare a building with energy measures to a reference building, which is similar but without the measures being installed. The Tidstegen tool can also be used by energy companies for the climate assessment of, for example, different investments in their district-heating networks.

The user of the tool feeds it with energy data (on produced and used electricity, heating and cooling) for the reference building and for each of the case studies to be analyzed. The reference building, which could be a current building in the case of retrofitting or a base alternative in the case of new construction, is entered by the user. Energy data should have a high time resolution, where hourly data is preferred. If the building is connected to a district-heating network, the user selects this district-heating system if it is available in the tool. Otherwise, the idea is that the local energy company adds new district-heating data in the tool according to a specified method. Initially there will be three modelled district-heating grids available in the tool, a small, a middle-sized and a large, if local data is not available. Data on the electricity system (North European) is already in the tool with three future scenarios that are updated by the coordinators of the tool. The tool then calculates the difference in climate impact between each case study and the reference building and presents the results in numbers, diagrams and bars.

The calculations currently only consider energy use and energy conversion during the operational phase. Energy used to produce building materials has not been included in the project. For this there are other tools available.

There are currently several activities where a tool like Tidstegen would be very useful. The benefits for the construction and real estate industry are, among other things, that they are able to plan energy solutions from a climate perspective at an early stage and that they can better see the consequences of different choices, even if the consequences of energy conversion occur beyond the borders of Sweden. Energy companies see the benefit in that climate-smart decisions in buildings will help the energy system to develop in a sustainable direction. To accomplish that, tools and environmental assessment methods like the Tidstegen are needed.

The actual consequences of a measure are always uncertain. Tidstegen estimates the consequences with models, which are always simplifications of the complex reality. Results from the tool Tidstegen will also probably be considered controversial for some, and the results are not always intuitive. This type of system effects should rather be seen as indicative and used for increased understanding of the systems to which the building is connected, rather than counting the exact climate impact for different energy solutions.

A widespread use of the tool, however, requires that it is user-friendly and free of bugs. Our next step is therefore to test the tool in several pilot projects. As new knowledge and new data are generated, the tool will also need to be updated to avoid becoming outdated. After the pilot projects have been carried out the tool will be available on IVL:s webpage.

Increased flexibility at the grid edge is required to achieve ambitious climate goals and can be provided by smart energy solutions. By systematically reviewing the literature, we provide an overview of the potential flexibility of different residential electrical loads for France, Germany, Sweden, and the United Kingdom. While 85% of the studies aimed to identify potentials for shifting electrical energy use in time, the other 15% aimed to identify energy-saving potentials. Most of the data were found for the German and British electrical systems. A wide range of flexibility measures (e.g., price mechanisms, user-centered control strategies for space heating and water heating, automated shifting of appliances' use, EV charging algorithms, and consumer feedback) and methods (e.g., simulations, trials, and interviews) have been used. Potentials obtained from the literature have been upscaled to the national level, including corresponding effects in terms of carbon dioxide (CO2) emissions. The results show that between 2% and 18% of residential sector electricity in the four countries could be shifted, resulting in total emission reductions of 10 MtCO2 from peak shaving, or 24 MtCO2 per year if optimizing the deployment of renewables. The literature identifies substantial economic, technical, and behavioral benefits from implementing flexibility measures. In all the cases, it seems that the current regulatory framework would need to change to facilitate participation. Recognized risks include higher peaks and congestions in low price-hours and difficulties in designing electricity tariffs because of conflicts with CO2 intensity as well as potential instability in the entire electricity system caused by tariffs coupling to wholesale electricity pricing.

This report describes the work performed by IVL Swedish Environmental Research Institute (IVL) and co-funded by Stiftelsen Institutet för Vatten- och Luftvårdsforskning (SIVL) and Blixt Tech AB. Increased flexibility at the grid edge is required to achieve ambitious climate goals and can be provided by smart energy solutions. Such solutions are expected to support the ongoing shift on the supply side towards more renewable generation (both on grid and distributed) and to offer consumers the opportunity to reduce costs by demand shifting. In combination with better information and automation to optimize energy use, grid edge solutions can take customers a step forward to become prosumers.

Using a systematic review of the scientific literature, an overview – for France, Germany, UK and Sweden – is provided of the potential flexibility of different residential electrical loads. The potentials obtained from the literature have been upscaled to the national level, including the corresponding effects in terms of carbon dioxide (CO2) emissions. The results show that between 2% and 18% of the electricity from the residential sector in the four countries could be shifted, resulting in total emissions reductions of 10 MtCO2 from peak shaving, or 24 Mt CO2 per year if the flexibility would optimize the deployment of renewables. Additional incentives are needed, and changes are required in energy price mechanisms and tariffs to make flexibility economically feasible on the market.