Legislation
From 1 January 2023 climate requirements have been set for construction. Now, new emission factors applicable from 2025 for buildings are being negotiated among the political settlement parties at Christiansborg.
Requirements for the climate impact of buildings and life cycle analyses are crucial to save CO2 in construction. 40 percent of CO2 emissions originate from construction, so it makes sense to set requirements for the climate footprint of building components.
What doesn’t make sense, however, are the calculation assumptions for the climate requirements for solar cells.
The calculation assumptions distort the value of solar cells and are
out of tune with reality.
This weakens the climate-related incentive to install solar cells on buildings, which inhibits the green transition. Effectively, backwards legislation contributes to increasing the overall climate footprint.
This is highly problematic in light of the climate and supply crisis and the need for the production of much more green electricity. Independency of Russian gas is of utmost importance.
Energy policy has become security policy.
Where lies the issue?
Solar cells and the production of renewable energy is a complex quantity that cannot be considered in the same way as other building components, the CO2 footprint of which is considered separated from the building.
Solar cells are part of the energy system and must be considered as such.
The climate burden from solar cells is primarily made up of the relatively large amount of electricity used in the production of the panels.
Under Danish conditions, the energy payback period is 1-2 years.
With an expected lifespan of more than 30 years, you get the energy at least 15 times over. From an energy point of view, this speaks for the solar cells.
A closer look at the calculation assumptions shows how these are out of tune with reality and put the solar cells in a bad light.
Solar cells are counted twice in the accounts
Klimabelastningen evalueres over en 50-årig periode i LCA-beregningerne. I den periode antages solcelleanlægget at blive udskiftet efter 25 til 30 år, og tæller altså dobbelt.
Udskiftning af solcellerne indregnes med samme klimaaftryk som ved år 1, det vil sige der ikke tages højde for den teknologiske udvikling i perioden, hvilket må siges at være stærkt misvisende.
The climate impact is evaluated over a 50-year period in the calculations. During that period, the solar system is assumed to be replaced after 25 to 30 years, meaning it counts double.
Replacement of the solar cells is calculated with the same climate footprint as in year 1, i.e. the technological development during the period is not taken into account.
In principle, it is not realistic that solar cells are replaced after 25 to 30 years.
The 25 to 30 years are in reference to the suppliers' performance guarantee and cannot be equated with the lifetime of the solar cells. The lifetime of solar cells is longer.
The experience of the solar industry shows that after 30 years of life, the solar system continues to provide at least 80 percent of the original performance.
It would be more realistic to assume that the solar cells are not replaced and are only counted once in the 50-year accounts, as they would remain on the building and continue to produce power throughout the period, albeit with a lower degree of efficiency after the performance guarantee expires.
New emission factors
The new emission factors that are being negotiated by politicians right now are going to put solar cells in an unreasonably bad light.
The emission factors are calculated on the basis of the Danish Energy Agency's, Energistyrelsen, projection of renewable energy in the Danish electricity system, where solar cells play an important part in the reduction.
Therefore, the calculation method is circular and rather an expression of a marginal CO2 displacement.
The solar industry's own calculations show that over half of the solar panels included in the study emit more CO2 than they save.
This means that the incentive to incorporate solar cells into construction disappears. It goes without saying that this is problematic for construction and the green transition.
However, the calculations show that virtually all solar panels (with the exception of the calculation based on the generic data) contribute to a CO2 saving in the building, if the solar system is not replaced and does not count double in the climate impact over the 50 years.
Such an approach would be more fair - and correct - for the solar cells.
Data is outdated
The generic data about solar cells is from 2009. The technological development in the field of solar cells has not stood still for 15 years. On the contrary.
Solar cell technology is undergoing rapid development and the panels must be expected to have a significantly higher efficiency in 25 to 30 years, and a significantly lower climate burden.
The climate footprint for solar cells in the production phase is today more than halved compared to 2009, and the solar cells have also become far more efficient during the period.
Unfortunately, current calculations do not take this into account. This paints an inaccurate picture of modern solar cells’ climate footprint.
Roof-integrated solar cells
With the current emission factors and calculation assumptions roof-integrated solar cells are effectively already CO2-emitting in terms of sustainability.
This emphasizes how skewed the calculation assumptions are. And it is devastating for the solar industry.
The climate footprint for manufacturing the entire building-integrated solar roof is included in the calculations. Correspondingly, credit is only given for the energy within the energy framework.
In practice, approximately 10 to 20 percent of the energy can be credited per floor, while the remaining CO2 displacement is not included in the calculation.
This means that the building-integrated solar cells displace more CO2 than is credited in the calculations and thus become CO2 emitters.
The technology risks being poured down the drain due to the calculation assumptions.
Not just a building component
There is no doubt that many factors must be taken into account in the calculations of solar cells' climate impact.
This makes it all the more surprising that the solar industry has not been consulted in the authorities' work to determine these important calculation assumptions.
Solar cells are more than just an isolated building component.
They are part of the energy system and pave the way for much of the green power we so badly need.
Solar cells contribute to solving the climate and supply crisis, and the safety of all of us.
Therefore, it is time to adjust the prerequisites so that solar cells are put in the correct light.
