Equip yourself to lighten your heating bill published in "Le Particulier" n ° 995, December 2005
by Valerie Valin-Stein
Why invest in renewable energy or more efficient energy processes?
The announced shortage of oil and the surge in prices will weigh more and more heavily on our heating budget. It is therefore better to anticipate and invest now in the installation of energy-efficient equipment.
From 0,39 euros per liter at the start of 2004, the average price of heating oil had risen to 0,68 euros at the end of October 2005 (latest statistics from the Ministry of Industry), up 74%. For propane gas, the change is around 27% over the same period. For natural gas, it will exceed 30% with the increases obtained by Gaz de France. This surge in prices is not due to temporary restrictions on production, as was the case in 1973 and then in 1980, but to the increase, no doubt lasting, in world consumption of oil and gas (particularly in China and India).
This means that the prices of these energies should remain at high levels for a long time. As for electricity, whose price changes like inflation, it remains much more expensive than natural gas or fuel oil. And the privatization of EDF, added to the cost of renewing its nuclear power plants, risks pushing its prices up. However, your heating bill is not inevitably doomed to follow these upward curves.
“We could, from today, build buildings that consume at least four times less energy,” says Alain Borna rel, from Tribu, a design office in environmental quality in the building. While a house that meets current standards consumes around 80 kWh / m2 / year of heating, we know how to build houses that are satisfied with less than 30 kWh. This represents, for a house of 120 m2 heated by fuel oil, a difference of 400 euros per year. The fact remains that such a performance can only be obtained with materials and equipment that are elaborate and complex to implement, and therefore more expensive.
The damping criterion.
The question is to know if, and after how many years, the initial additional cost will be compensated by the induced energy savings, which corresponds to the criterion of "time of return on investment" (the additional cost divided by the saving annual). The same goes for an existing building, where it is possible to improve the insulation, or to replace old heating equipment with other less energy consuming. Something bad is good: the more expensive the energy, the greater the possible savings, and therefore the shorter the payback time. We have carried out all our calculations on the basis of foreseeable tariffs in 2006 and on a "disaster scenario" envisaging an increase of 50% compared to 2005. Furthermore, the cost of energy saving equipment will be reduced in 2006 compared to 2005, with the increase in the tax credit to which they give right, when they are installed in an existing dwelling.
This credit would go up to 50% for equipment such as heat pumps and solar water heaters. However, only equipment and materials meeting specific characteristics give entitlement to the tax credit, and expenses are withheld within the limit of 8000 euros for a single person and 16000 euros for a married couple (plus 400 euros to 600 euros per dependent child). In new housing, individual or collective, the regulations (known as "thermal regulations", or RT 2000) impose an overall performance in terms of energy consumption, and leave the manufacturer to choose the means to achieve this: insulation reinforced, use of “passive” solar contributions (for example by orienting living rooms to the west or south and by providing them with bay windows) or resorting to low-consumption heating methods. This performance is expressed by the ratio between the consumption of the home and that of a reference home (hence the expression “reference coefficient”, or Cref).
As of 1 September 2006, a new regulation, called RT2005, will impose on new housing a Cref of 15% lower than the one currently required.
The central heating premium.
The option that initially requires the least investment for heating a new home is all electric, with radiant panels (around 150 euros per unit) or an electric underfloor heating (from 30 to 35 euros / m2, plus floor covering). In all, between 3 and 000 euros for a 4500m120 house. In use, electricity is the most expensive energy, but it takes several years before this makes up for the difference in initial investment with other heating methods. Moreover, changing it is very expensive. “We do not know the evolution of the cost of the different energies. We must therefore be flexible, and for that to install central heating, ”analyzes Jean-Marie Carton, from the Confederation of Crafts and Small Building Enterprises (Capeb). Count 2 euros per unit for quality radiators and around 300 euros / m65 (excluding coating) for a hydraulic heated floor, or 2 euros for a house of 7800 m120. To supply this installation, an electric boiler costs around 2 euros; a gas boiler, 1500 euros; and a fuel oil, 2700 euros for a low temperature gas or fuel oil model. More expensive (from 3000 euros [gas] to 4 euros [fuel oil]), “condensing” boilers are however tending to prevail: their efficiency is higher (000% to 5000% against 103% to 107% for low temperature), because they recover heat from the exhaust fumes; and they will benefit, from 95, from a 100% tax credit (for models provided with a "CE type" certificate). This will put their net price at the level of that of low temperatures, for which the credit is only 2006%.
In addition, a natural gas boiler becomes more advantageous than an electric boiler after 2 to 3 years, this period being about 10 years with fuel oil. In existing housing, the replacement of a traditional model several years old, whose efficiency is 60% to 80%, by a recent high efficiency model can pay for itself in 3 to 6 years. However, the heating water produced by a condensing or low temperature boiler is at a lower temperature than that of a conventional boiler, the original radiators may be undersized. Changing the boiler is therefore not advantageous.