This project includes many innovative features which will indeed require some initial investments. Some of the technologies are available on the market off the shelf, but some others will be probably introduced as pilot projects.

Let’s go through a rough estimate of the initial investment costs. Table 1 shows a list of potential investments that are required by the project described in previous sections.

Table 1 – Zero Emission Workspace investment costs

Land – The estimate of the investment needed for the purchase of a suitable land bears a high level of uncertainty. The area required for the building is 600 m2, thus, taking into account the space for the car park and the energy generation facilities, it is likely that an area of 10000 m2 (2.5 acres) will be necessary, as illustrated in figure 2. Land cost varies between different locations across England, which means that it is possible to better estimate this figure only once the region has been identified.

As a gross estimate, we set the cost to £100K, which is a reasonable amount for an average land of this size. It is clear that this cost could be either half or twice as expensive as £100K, nonetheless this estimate gives at least the magnitude of the investment required.

Figure 1 – Zero Emission Workspace map

Figure 1 shows how this 2.5 acre land could be used:

  • 600 m2 will be occupied by the zero carbon commercial building
  • An area will be occupied by the electric vehicle car park and filling station
  • An area will be used for the installation of the wind turbine(s), the energy storage facilities and the electricity connection with the electric grid
  • An area will be used for the car park
  • The remaining space will be used for other uses; one possible use could be an exhibition centre for showcase of new energy technologies. This additional space will not probably be part of the first phase of the project because of possible initial investment cost limitation. If we introduce an additional exhibition centre we’ll need to power it with renewables and an option might be to install additional PV solar panels on top of the exhibition centre’s roof

Full planning application – In England, a full planning application for the construction of a commercial building, a car park and all its faci lities costs £8040.

3 storey zero carbon commercial building – The estimate of the cost of the construction of the commercial building described in previous sections is worked out form the average cost per square foot of commercial construction by region in the US. The cost per square foot varies significantly with location: the highest cost in the US is in New York where in August 2009 the average cost was $215/sq ft (see diagram in figure 2).

Figure 2 - Cost per square foot of commercial construction by region in the US (source: Reed Construction Data – RSMeans)

Assuming for London the same cost per square foot as New York (assumption which is probably not far from reality), for a 600m2 (6400 sq ft) building the total adds up to $1,376,000, which is about £955K. 

Not surprisingly, the investment cost for New York or London city is quite high, but we need to bear in mind that the actual realization of the project could be somewhere near London, though out of the city. It could happen that the more we go out of the city the cheaper will be the cost of the construction. For example, the cost could fall to the Los Angeles levels ($176/sq ft) or even to the Washington D.C. ones ($162/sq ft). However, let’s keep the estimate as high as the New York City’s average cost and we can still lower it later if it comes out it is too high.

Passive house technologies – According to the German Passive House Institute, additional thermal insulation in walls, roof and ground slab, Passive House windows, ventilation system with heat recovery (and taking into account the savings from smaller oil tank / boiler and the elimination of radiators), has a cost of about €15000 (£12500) for a single family home. This cost can be rounded up to £20000 for a 3 storey commercial building.

Kitchen appliances – each office needs a full set of kitchen appliances, as described in previous sections. If we assume that a set of high efficiency appliances costs £4000, the total for 6 offices amounts to £24000.

50 KW wind turbine – A 50 KW Coemi Skywing three blade wind turbine costs about £160,000.

210W PV solar panels – 270 Kyocera 210W PV solar panels cost £750 each, which adds up to £202,500.

Thermal solar panels – Typical residential thermal solar water heating systems cost about £4000 and they are enough for a household of 5 people living in a semi-detached house. Let’s scale it up to a commercial building hosting about 20 people per office, 120 people in total: that would be 24 such systems. 

Let’s assume that 15 thermal solar systems are enough to provide hot water for all the people in the building during working hours. In fact, we need to consider that the hot water consumption per day per person is much less in an office than at home. We usually have a shower at home in the morning of we have a bath at home in the evening. Some people cycle to work and they have a shower at work, but it is usually a small percentage.

15 thermal solar systems would occupy roughly 75 m2 on the roof, with an initial investment of £60,000. 

Rainwater harvesting system – The rainwater harvesting system collector should be installed on a large flat area which is usually the roof of a building. In our case, the roof is already totally occupied by the arrays of PV and thermal solar panels, which would leave no space for the water collector. 

The solution is to make the three systems (PV solar panels, thermal solar panels and the rainwater harvesting system) coexist on the roof without compromising the performance of any of them.

Figure 3 – Rainwater-solar system

Figure 3 shows what we can call a “rainwater-solar” system. On top of the roof, solar panels are installed on a metallic protection grating which let the rainwater filter through into a water tank underneath. The water is collected in the tank and drained down into an underground storage tank where it is appropriately treated, filtered and purified.

In England solar panels need to be installed with an inclination angle of about 30 degrees, so rainwater slides over the panel surface until it falls off.

Water tanks are always installed on top of the roofs in order to collect water as clean as possible. If we installed it at ground level there could be an increased risk of contamination from animals or other pollutants. It may be argued that when rainwater slides down over the solar panels surface it gets contaminated by the dirt accumulated on them, which wouldn’t happen if we collected the water directly without allowing it to touch anything. 

Even though this objection could be partially true, we should remember that rainwater is never pure, it is usually rich of pollutants and, even without solar panels on the roof, rain water gets in contact with the metallic protection grating where all sorts of things may accumulate, like dead leaves or bird excrements. This is essentially why an appropriate purification and filtering system is needed to make rainwater usable for human needs.

A rainwater harvesting system for a commercial building like the one under analysis is estimated to cost about £8000. This could be the cost for a standard system, but in our case we want to try out a combined solar-rainwater system on the roof and for this reason the initial investment for this kind of technology might result to be slightly higher.

Pumped heat energy storage system – Assuming we can scale down to 2 MWh an Isentropic pumped heat energy storage system, at £35/KWh, the cost amounts to £70000.

There are other energy storage options that have been analysed in previous sections, such as Li-ion batteries. Zero Emission Project will be in contact with all the companies that may potentially be interested in testing their energy storage systems on a micro-generation environment like the one proposed here. 

For the scope of this cost estimate, let’s assume that any energy storage system has a unit cost of £35/KWh, so that the total cost for any 2MWh system is £70000. 

Fleet of 6 electric vehicles – Six electric vehicles will be available to use in an eco car park. The Mitsubishi iMiEV electric vehicle is likely to meet the expectation: it will be available in the United Kingdom from January 2011, with a price starting at £38,699 (including 17.5% VAT) before deducting incentive of £5,000 from the government, to become one of the first electric battery cars on the market. 

2011 is predicted to be the year of electric cars (Nissan and Vauxhall are going to launch their models on the market) and it is likely that the price will go down after 2011.

Let’s consider a unit price of £35,000, which adds up to £210,000 for 6 vehicles.

Grid connections – The estimate for the total cost of all the necessary grid connections is not easy to work out. From other renewable energy projects such as wind farm developments, the cost range could be set around £90,000. This cost might result to be lower since the electric system required for this project is expected to be smaller than the one necessary for a big wind farm development.

Consultant fees – Consultant services will be required for many aspects of the projects, which could be summarized as follows:

  • Financial services
  • Land and estate agents
  • Civil engineering and building design
  • Renewable technology consultants
  • Passive House Institute consultants

The total costs for these professional services have been estimated to be £80,000. It is clear that the actual cost could be less or more than this amount and it depends on many different factors which are not known at this stage of the project.

The estimate for the total cost of the project is about £2M. Since this estimate has been worked out with a high level of uncertainties, is anticipated to be about ±20%.