The definition of near 0-energy buildings, a short treatise on the EU directive on 0-energy buildings
(EPBD recast 2010)
For some years 0-energy buildings and energy neutral buildings are in sight and discussed. There are many variations in terms and definitions,. Some years ago I analyzed the verb , and concluded it consists of 3 elements: the target, the source and the applied system ( building) .With these three elements many combination are possible, like this one for instance : “100 % renewable energy community “ , or 0-emissions building(s). Later the Dutch consultancy W/E developed guidelines for the definitions, for a government agency . This however has never become a national standard in the Netherlands.
In fact, 0-energy is not possible of course. The 0 points usually to the fact that 0-fossil fuels are used, not energy itself. Or better : 0-impact from energy use. : which implies only use of energy from streaming resources: resource that are naturally renewed so that there is no effect on depletion, or side effects of their use (not including the energy for production of conversion devices) . Its good to notice that Solar radiation and all direct secondary flows are the only sources that have a net contribution to the global energy stock (when stored) , all other sources deplete the earthen available stock. Its obvious that in general we attempt to increase our use of solar radiation related energy flows. Without going into too much detail we can give a short practical definition of a 0-energy building: The building acquires all its energy from renewable sources on the building or from within the plot size belonging to the building. The electricity grid may be used to to balance shortages and surpluses, as temporal stockage. ( mainly store surplus in summer, take back in winter)
Energy-neutral in that case is that the building uses only renewable energy , but not per se from within the building plot, they may be imported from elsewhere. Distant Wind turbines, or even “ green “ electricity in general.
This is important to keep in mind, when we start looking into the Legal requirements. Since meanwhile regulations have been developed based on the European directive known as EPBD recast 2010,which are implemented by 2018 and beyond. The directive requires that all public buildings from 2018 on , and all other buildings form 2020 on, should be nearly 0-energy. And you probably already feel that this is ground for a lot of discussion , especially the addition “ nearly”
What is the formal description ? Article 2 in the EPBD recast Directive states:
‘nearly zero-energy building’ means a building that has a very high energy performance, as determined in accordance with Annex I. The nearly zero or very low amount of energy required should be covered to a very significant extent by energy from renewable sources, including energy from renewable sources produced on-site or nearby;
Nearly zero , in fact implies close to 0 , and does not say anything about the balance: It simply implies that all demand is supplied form renewables. Which does not mean that the demand should be low, if only its in (near-) balance with (renewable) supply . ( and the amount of solar energy is in fact not of interest, its a free , non depleting and polluting source) Nevertheless the article speaks indeed of a “very low amount of energy” , to continue stating that a significant part should come from renewables. ( the near balance thus). But then the article goes wrong anyhow: “ from sources on site or nearby” . In that case the 0 is superfluous, if it can come from outside the building plot. Besides the double use of nearby and nearly is confusing anyhow in one definition. I already met the first civil servant that stated in a European conference that near was meant as “nearby sources” and not near 0 ….
But even more interesting are the official translations to apply in each EU country ‘s legislation. The Dutch version is:
2. „bijna-energieneutraal gebouw”: gebouw met een zeer hoge energieprestatie, zoals vastgesteld volgens bijlage I. De dichtbij nul liggende of zeer lage hoeveelheid energie die is vereist, dient in zeer aanzienlijke mate te worden geleverd uit hernieuwbare bronnen, en dient energie die ter plaatse of dichtbij uit hernieuwbare bronnen wordt geproduceerd te bevatten;
In fact the 0 has disappeared overall here, and only speaking of “nearly energy neutral”. Which in fact is a legally incorrect translation ( if English is the source) . The Dutch version also speaks of “ aanzienlijke mate”, which can be to back-translated as : substantial share” which is more soft then “significant” . And “dient te bevatten” , back-translated as “ should contain” ( …energy produced on site or nearby), which is also very weak, and the system border becomes quit irrelevant this way.
The German language translation states: “ niedrig-energiegebaude ( in the offical translation) , which is a “low energy building” , and in fact only refers to demand, which should be low, but nothing about supply ( in the term itself that is) .
France speaks of a ” bâtiment dont la consommation d’énergie est quasi nulle’ : as does Spain: edificio de consumo de energía casi nulo, : back-translated as : nearly zero energy consumption. Both have nearly 0 copied, but introduce consumption ( instead of building) , suggesting only ‘demand’. While Sweden for instance sticks tot the original definition: nära-nollenergibyggnad.: near zero energy building
Other articles detail some of the phrases used, like “energy performance”:
Art 4. ‘energy performance of a building’ means the calculated or measured amount of energy needed to meet the energy demand associated with a typical use of the building, which includes, inter alia, energy used for heating, cooling, ventilation, hot water and lighting;
In other words: building related energy, plus (hot) water ( inhabitant related) . But without “comfort and luxury energy” , for appliances like laundry machines and television. Interesting is the use of the phrase: ‘measured amount of energy’, which implies end user demand. That is the correct way of course, since primary energy would not make sense when leaving out fossil fuels in a 0-approach.
And art 6 states with regard to “renewable sources” :
Art 6. ‘energy from renewable sources’ means energy from renewable non-fossil sources, namely wind, solar, aero thermal, geothermal, hydrothermal and ocean energy, hydropower, biomass, landfill gas, sewage treatment plant gas and biogases;
Basically all energy not from fossils, and therefore including energy from bio-fuels. And it can be discussed if landfill and sewage gas is a renewable source…. However without nuclear energy.
And in art 14 it is written that all countries should aim at the “ most cost optimal level” of energy performance :
Art 14. ‘cost-optimal level’ means the energy performance level which leads to the lowest cost during the estimated economic lifecycle, where: etc
How “ near “ is near, is, with this statement, in fact not an energy question but a cost optimum question, undermining all previous targets.
Moreover , part of thedirective is also requiring member states to take measures to formulate ambitions for renovating buildings towards near 0-energy buildings. This spring all countries should have send in their plans to the EU. Which is also supported by measures in last year’s Energy efficiency directive.
In the annex to the EPBD recast more details are given how to calculate the near 0-energy targets. As follows:
1. The energy performance of a building shall be determined on the basis of the calculated or actual annual energy that is consumed in order to meet the different needs associated with its typical use and shall reflect the heating energy needs and cooling energy needs (energy needed to avoid overheating) to maintain the envisaged temperature conditions of the building, and domestic hot water needs.
2. The energy performance of a building shall be expressed in a transparent manner and shall include an energy performance indicator and a numeric indicator of primary energy use, based on primary energy factors per energy carrier, which may be based on national or regional annual weighted averages or a specific value for on- site production.
Here things are mixed up, and the two articles are contradictory:
The first mentions energy that is consumed, while the second refers to primary energy. Notwithstanding the fact that energy cannot be consumed, its meant to say end use , the demand in the building. Which is not the same as primary energy. Its confusing , and strange since primary energy of fossil fuels is completely obsolete when aiming at a renewable energy based society: primary energy is an artifact from the fossil based era, in which solar energy was seen as primitive. But the route from solar radiation to electricity is far more effective in the direct form, as it is via the solar radiation to biomass and sedimentation route that creates fossil fuels.
Besides , lighting energy has disappeared in the annex articles.
A few remarks at the end of this exploring essay. If a building is a 0-energy building, as meant by the definition in the introduction, energy in fact is no issue anymore. The energy is for free ( solar radiation , wind, earth heat, etc) and harmless. The criterion is then re-defined as how much materials have to be invested in either reducing demand or making production available in the right form.
The energy question has become a materials question. ( another reason why primary energy has become senseless as a parameter) And materials require , ( in addition to the mass resources) substantial energy amounts to be produced . Which is now not taken into account, though you could read that in “ energy demand over the lifecycle” includes materials energy impacts. But I guess that’s wishful thinking from the author. Nevertheless I like to refer to a recent research I carried out that the optimum for a 0-energy building is not in heavy insulation, but that a lower insulation level combined with a bit more production provides a better overall performance (energy and materials together.)
The remaining question is now how the EU states will in fact deal with this EPBD recast requirements. Especially in a country ( the Netherlands but also Germany for instance) , which is already introducing , not near but net 0-energy buildings. In the Netherlands a large scheme to renovate (100.000) houses to “ energy-invoice-less houses” : people in principle do not get a energy bill anymore: The idea is copied from the mobile phone subscription: you get a bundle for free. ( only if the inhabitants go beyond their bundle due to spilling behavior they will have to pay). To release the more strict 0-energy approach into the energy neutral approach in the Netherlands, puts this development backwards again.
Based on these findings I propose to rephrase the EPBD recast target into a more practical way as follows:
All new buildings are required to be designed as 0-energy buildings. Therefore determined to acquire all necessary energy from within their building plot. The addition : nearly , is then redirected towards a investment question ( relating to the cost optimal part): The building may, to spread investments , be constructed as a near 0-building. For instance; Only half of the solar panels is installed, a second batch in ten years or so. The remaining part, the difference between 0 and near, has to be supplied from “ nearby” renewable resources, for instance as certified ‘green energy”.
It is therefore in any case energy neutral, and 0-energy prepared. However still with a defined ‘near’: otherwise 100% green energy could still close the deal.
r.rovers , january 2015
www.sustainablebuilding.eu ( see projects-maxergy for the referred research)
article 2 in different languages:
2. „Niedrigstenergiegebäude“ ein Gebäude, das eine sehr hohe,
nach Anhang I bestimmte Gesamtenergieeffizienz aufweist.
Der fast bei Null liegende oder sehr geringe Energiebedarf
sollte zu einem ganz wesentlichen Teil durch Energie aus
erneuerbaren Quellen — einschließlich Energie aus erneuer
baren Quellen, die am Standort oder in der Nähe erzeugt
wird — gedeckt werden;
2) «bâtiment dont la consommation d’énergie est quasi nulle»,
un bâtiment qui a des performances énergétiques très
élevées déterminées conformément à l’annexe I. La quantité
quasi nulle ou très basse d’énergie requise devrait être
couverte dans une très large mesure par de l’énergie
produite à partir de sources renouvelables, notamment
l’énergie produite à partir de sources renouvelables sur
place ou à proximité;
2) «edificio de consumo de energía casi nulo»: edificio con un
nivel de eficiencia energética muy alto, que se determinará
de conformidad con el anexo I. La cantidad casi nula o
muy baja de energía requerida debería estar cubierta, en
muy amplia medida, por energía procedente de fuentes
renovables, incluida energía procedente de fuentes renova
bles producida in situ o en el entorno;
2. nära-nollenergibyggnad: en byggnad som har mycket hög
energiprestanda, som bestäms i enlighet med bilaga I.
Nära nollmängden eller den mycket låga mängden energi
som krävs bör i mycket hög grad tillföras i form av energi
från förnybara energikällor, inklusive energi från förnybara
energikällor som produceras på plats, eller i närheten,