The Vaasa Housing
Fair
West Finland
DESCRIPTION OF THE PROJECT
Used technology at the Housing Fair in Vaasa, Finland 2008 is:
- A fuel cell power plant running on biogas
- Combination with a micro turbine also running on biogas
- Utilising sea heat from piping submerged under the sea bottom with a novel technique
- A low temperature district heat network directly providing low temperature heat and cooling to the houses
- Passive/low-energy building utilising state-of-the art solutions applicable for large production volumes
The housing fair consists of 42 single-family and small houses and 3 apartment houses. In this paper we will introduce the used energy supply technology. Based on official information from a pilot study of design conditions conducted by the Geological Survey of Finland and the technology suggested for the fair, the self sufficiency has been estimated. We conclude that there are reasonable conditions for self sufficiency in both heat and power for at least 90% of the average year.
FACTS
Preliminary calculations show yli-self sufficiency in energy of 120% for electricity and 160% for heat.
The calculations are using specific consumption values based on
experience
as declared in this paper. Carbon dioxide emissions may be reduced
by nearly 1800 t/a.
The system is target for measurements, follow-up will be performed and the benefits and possible drawbacks evaluated in further research.
1. Low energy sea sediment heating and cooling
The sediment at Suvilahti bay shows very interesting features.
Western Finland Office of Geological Survey of Finland carried out
measurements to control the results of earlier measurements made by
Mateve Oy.
The sediment accumulates solar energy during thesummer and the ice serves as an insulator during the winter. This energy is now going to be utilized based on new possibilities for e.g. heat pumps. Whole suburbs can be supplied with local heat networks. Ground sediment can be used from water areas but also ground underneath of parks, roads and even buildings can be utilized with different drilling techniques.
The local heat network can reduce the overall energy consumption of suburbs as much as 70 % leading one step further towards the climate goals.
Because sea water is
well known to be tricky, a special method was developed. A new
coaxial pipe, referred to as Refla, was drilled horizontally into
the sediment. Eight kilometers of this Refla pipe was sunk under
the Suvilahti bay. An ethanol-water mixture is going in the center
of the pipe, turning at the end and flowing back at the periphery
of the pipe. The outer side is optimized and has a large heat
exchange surface to the sediment. Liquid from the network houses
having delivered its heat flows back to the Refla pipe. Heat pickup
is efficient due to the construction, which seems to be robust,
too. Installation is relatively easy: No digging, and no rock
drilling were necessary, only horizontal drilling into the sediment
is needed.
The collector pipes are drilled horizontally from the shore into the sediment. At the shore the pipes are at the same level, but in the sediment the pipes are bored to different depths. Thus the distance between adjacent pipes can be significant already due to the height differences. The collector pipes are connected in parallel to so called collecting wells, which are then connected with the Low Energy Network.
The operation of the Refla pipe has been developed at Tampere University by professor Antero Aittomäki and at Royal Institute of Technology (KTH, Stockholm) in a five year research program investigating the qualities of the Refla pipe (Research results M. Lieskoski).
Inhabitants get access to the energy by an entrance fee, after which they needn't to worry about heating contracts any longer. The investment was half a million euro, i.e. somewhat over 10,000 € per household. The tariff is quite attractive for the inhabitants. Entrance fee is 1500 € and operation is 2.5 €/m2/year + VAT.
2. Biogas from the Suvilahti sediment
It is expected that an interesting amount of biogas,
mainly methane is naturally produced in the Suvilahti bay sediment.
Also different means by which this abundant natural biogas could be
collected for utilization has been discussed. However basic
investigations of the gas volumes that could be available are
currently lacking and could be an object for future investigation.
Also method comparisons from the scientific world for ways to
collect the gas from the undersea sediment would be needed.
3. Biogas micro turbine with landfill gas
Instead of flaring off the gas from the now closed
Suvilahti landfill not to say letting the gas into the sky, soon
the Housing Fair can have 100 % ecological energy from the biogas.
Electric power of 130 kW and heat of 230 kW can be produced in a
micro turbine plant, built and operated by Sarlin Oy based on an
agreement with Vaasa City. The piping system to recover the gas
from the landfill was built in 2005. Already at that point Sarlin
and Vaasa discussed the possibilities to utilize the biogas. The
Housing Fair raised a steady wind blowing in the right
direction.
The plant is operated at a distance from Vantaa near Helsinki. No personnel is needed on site. A distributed control system monitors the plant and the operation data is stored in a computer. Electric power, gas composition, temperatures and pressures are monitored as well as heat production. Alarms happen quite seldom and can often be handled remotely. A fully automatic shutdown system stops the pumping, shuts down the valves and starts ventilation, if preset alarm levels are passed for gas composition or control room gas indicators.
4. Wind turbines
The coast of Western Finland is among the best areas in
Finland for wind power. The regional plan for the coastal area and
for the Ostrobothnia region contains several areas for large wind
power parks also in the 200-500 MW region. Also a number of small
wind power parks are part of the plan, also some in the immediate
vicinities of Vaasa, as well as some not so small.
Preliminary discussions have taken place regarding a limited amount of wind power in the Suvilahti area, in a form and extent that would fit appropriately to the values of the housing fair area. There are a number of domestic and international suppliers that could deliver the windmills. E.g. in Vaasa a fast growing company is The Switch and there are other interesting suppliers as well.
A handful of wind turbines of modern sizes could deliver even a few megawatts of electricity, or smaller ones could also still considerably contribute to the self-sufficiency of the Suvilahti area.
5. Fuel cell power plant with landfill gas
A first of its kind solid oxide fuel cell power plant
will provide the Housing Fair with additional ecological
electricity and heat. Further utilizing the landfill gas, a Solid
Oxide Fuel Cell unit from Wärtsilä will produce 20 kW
electricity and 14-17 kW heat running on the biogas.
A SOFC power plant runs on high temperatures around 750 °C and is characterized by very high efficiency. The range of fuel gas that such a plant can accept is wider than for most other fuel cells. Except hydrogen also methane, CO and biogas can be used. The emissions in form of rest products are mainly water and carbon dioxide. Thus, running on biogas the plant is GDP=0 and totally carbon dioxide neutral.
Cost structure of a fuel cell power plant consists to only 30 % of the fuel cells themselves, while 70 % comes from other system components and manufacturing. These components are heat exchangers, valves, power electronics, automation, piping, structures etc. This can be a reason why Finnish industry has so remarkably increased the interest in utilizing this technology in their own products lately.
6. Solar heat
The single-family dwellings are well suited to be built with
integrated solar heating panels. Solar panels have high
efficiencies when they deliver heat to relatively low temperatures.
This is especially relevant in the case of the Vaasa building fair
with the low-temperature Mateve local heating network. There are a
number of self-building courses for do-it-yourself with-your-mates
solar panels, well organized by Merinova Oy. These courses are
carried out in different places in Finland. The panels have a
decent quality/price ratio, and you experience the hobby aspect of
building them as well. Another good alternative are highly
efficient, modern vacuum tube solar panels. There are also
interesting innovations with concentrating solar panels.
Solar panels could still provide an interesting amount of heat further raising the energy self sufficiency of the area. Especially for producing warm tap water during the summer, the solar panels come handy. Another applicable solution lies in the heating of swimming pools. Preliminary discussions have been held with interested people.
7. Solar power
Solar power is sinking in terms of cost per kilowatt and rapidly
becoming more popular in Europe and other parts of the world. The
amount of energy that can be derived from solar cells is lower
compared to the total demand of the suburb, but still that amount
can contribute to the overall energy balance.
Also the visible effect of the solar panels, reminding of day-to-day attitudes towards renewable and efficient use of energy, counts. After all usage habits affect a lot of the energy used in homes, and habits are strongly connected to attitudes. Significant research has been done but is still needed regarding habits and attitudes since these do have a considerable impact.
8. Low energy - Passive house
The first house on the right when you come to the bungalow area is
a low-energy house built with a warm heart. The construction is
based on hollow, concrete filled EPS blocks. Expanded polystyrene
(EPS) is a lightweight cellular plastic material suitable for a
wide range of applications, in Finland referred to as
"styrox". It is an excellent insulating material which
exhibits consistent thermal performance over the range of
temperatures normally encountered in buildings. It is also used in
a wide range of other areas including packaging, buoyancy, panel
cores, bean bags and civil engineering.
The construction block is also called ICF, from Insulating Concrete Forms. The hollow EPS forms are erected at the construction site, then filled with five or six inches of reinforced concrete. Unlike traditional concrete forms, which are removed after the concrete cures, ICFs are left in place. Because the concrete core is surrounded with EPS insulation, ICFs provide superior R-values and sound-deadening qualities. But because reinforced concrete is at the center, they also offer the strength to withstand the forces of nature that would destroy houses built using traditional construction methods.
EPS blocks are also considered a good choice considering
hurricanes, and fire.
This house has a U-value of 0.16 which can be compared to the
current building norm in Finland of 0.25 for new houses. The house
is an atrium house with a swimming pool in the atrium. Sauna and
guest house are situated on the other side of the pool.
Low-temperature heat from the sea bottom is supplied via a heat
pump to both the house and the pool. Monitoring the energy was
considered interesting. Thus a student from Novia University oAS
got a "hot" project to find a modern yet cost-efficient
solution to monitor the energy data on a continuous, automatic
base. Total electricity is measured and separately the electricity
to the heat pump. Heat energy is measured on the primary side of
the heat pump, and on the secondary side separately to the house
and to the pool. The data is transmitted over the internet from the
Kamstrup energy meters to the compatible client software in the PC
situated in the research facilities. A self-compacting database is
handling the long-term data, which can be accessed over a
web-connection from anywhere including the house-owner even from
long haul business trips.
Heat distribution in the low-energy house is via water pipes in the floor, even if the heating requirement will be very low compared to a normal house of the same size. The low-temperature network also serves for cooling the house during the summer. Thanks to the system here is a house with integrated cooling during the summer and heating during the winter. The low heat demand is secured by selective three-ply windows and above-norm thickness of insulation.
The crown, in the heart of the house, is the living room. A smoke-free open fire based on bioethanol provides a cozy feeling during the winter when it is cold outside. The fire is not supposed to supply much of heat, but the feeling. Thanks to the solution it looks like a large flat screen TV and doesn't even have a stack.
CONTACT DETAILS
Johan Wasberg
Development Director
Technology Centre Oy Merinova Ab
Vaasa, Finland
Email: johan.wasberg@merinova.fi
