Present: Ross McIntyre and Brent Clark from WattBlock, Luci, Alex, Paul, Neil and Peter Steen from the Strata Executive Committee
As noted above the consultants had previously provided us with several documents that had been folded into the substantial (72 pages) report embodying their advice and recommendations that we received by email yesterday. These are available in Appendices to this Blog.
In our Request For Quote document we had asked for examination of four models ranging from 18 separate solar installations to one servicing all 18 as one. In an earlier conversation it was agreed to cover a fifth model which is solar + battery. Brent expanded on the advantages and disadvantages of each model in turn including the solar system size required, estimated costs and savings, and the time for payback of the up-front cost. This analysis led them to recommend in the first instance our Model 4 incorporating an Embedded Network covering the whole complex because it showed the shortest payback time of 4.1 years and the best financial payback as a stand-alone investment. This would mean leaving the installation of battery storage to a subsequent stage.
The cost of the embedded network would be $19.2K while the solar panels delivering 18.2kW would cost $27.48K, a total of $46.68K. This system would deliver $10.976K of savings, while reducing energy consumption by 23,690kWh p.a. which is the equivalent to 25.1 tonnes of carbon emissions. This model is attractive to us because it provides a community solar system and reinforces our espoused principles such as it recognises that the rooftops are collectively owned, the model enables opt-out and opt back in by customers who want it, it is more efficient and cheaper than the status quo, and it is flexible enough to provide future options as technology and regulations change.
In further conversation it became clear that, notwithstanding that the consultants see this as the preferred model we in the Blackwattle Team prefer to go straight for Model 5, that is, the embedded solar network with battery storage. Due to the current cost of batteries this would mean the overall payback time would be increased from 4.1 to 6.7 years at an estimated total cost of $94.84K. The energy savings for Model 5 are, however, estimated at 35,145 kWh p.a. with carbon savings of 37.3 tonnes per year, quite a significant improvement.
The key features of an Embedded Network are that a ‘parent’ or gate meter is placed between multiple consumers (the embedded network), each with a ‘child’ meter, and the poles and wires of the national grid. This will allow the 18 townhouses to ‘bulk-buy’ energy together and get better electricity rates up to 30% cheaper than normal commercial rates. In conjunction with the community solar system, a second advantage is that a single ‘user pays’ billing system can be used providing an equitable solution for all owner occupiers and tenants.
Analysis of the solar access to rooftops over the seasons revealed that Block A (labelled Block D in the consultants’ report) on our Strata Plan has by far the best solar access year round. It is therefore recommended that the solar panels all be placed on the roof of Block A. It is further recommended that microinverters be attached to each panel so that individual panels can output power independently increasing system output and enabling the system to be expanded to add more panels if required in the future.
After the excellent briefing session we had a debrief the next day. At this point we became clear that we wanted to recommend to our Owners that we design and install an embedded network that was future-proofed by adding solar panels to completely fill the unshaded area of Block A. Together with the requisite storage batteries this would enable us to provide Electric Vehicle charging in owners garages and even to offer the Council two public charging stations outside our property in the adjacent streets, Sheehy and Cook.
This thinking fed into our focus on the potential for us to add demonstration innovation to the City of Sydney’s Sustainable Futures programs. Alex began work on this. We also decided to re-label our project ‘BlackwattleSolar’.
We then wrote the following email to the consultants:
We were very pleased with our session on Tuesday, thanks for the thorough and well-informed way you worked with us. We met again yesterday and have some more thoughts for your consideration.
Looking ahead and in the hope that we will receive further support from the Council, we want to include an option in which we fill the unshaded area of Block D with solar panels from the start giving us expansion possibilities without the need to use a crane again. This could perhaps be seen as Model 5A. Therefore, would you include this option with attendant costs?
With regard to the Block designations, the Strata Plan has your Block A as D and vice versa, the Blocks B and C are as on the plan. Would you please go through the report and change D to A and vice versa to avoid confusion ? There are a number of other changes needed in the Report: we will send a marked up copy in a few days.
So as to reassure owners, we will need to develop 10-year cash flow projections for several models. Could you do that? We can provide the models, which are variations on your options 4 and 5.
As we mentioned during the meeting, we wish to commission you to develop and run the tender process, subject to receiving the remaining grant funds which we expect imminently. We want to do that on the extended Model 5, following our finalisation of its specification when we receive the cash flow projections from you. That process will provide us with the necessary 3 quotations for the demonstration grant application.
In the new tender process I presume we are looking for two different contractors, one to handle the technical installation side and one to be the Embedded Network Manager/Licensed Electricity Retailer. In the case of the latter we expect to ensure that it includes Billing management and we want to ensure that we retain access to the data base.
So far as Battery type is concerned we would like to require that the tenderer cover a range of types beyond just Lithium/ion and indicate that we have a preference for Australian produced.
Finally, we have foreshadowed with our community our intention to hold an informal introduction of information about the project at a Brekky Bar B Q on Sunday, April 8th. If you and Ross are able to attend that would be terrific but is not essential . We are thinking that shortly after that, after checking to ascertain interest and depending on attendance, we will offer a slightly more formal meeting, either at the community centre or here on site where folk would have the opportunity to hear from and quiz you guys. On both occasions we plan to follow your recommendation that we encourage people to see the development as representing gains for them in both reduced energy costs and property values and worthy of 100% community support since anyone who wants to can opt out of direct involvement.
We would welcome your advice and assistance on ways to present the information and choices that is attractive and easy to follow. We will work on producing a one or two-sided flyer as a take away. We have decided to brand ourselves ‘BlackwattleSolar’ – we wanted BMSolar but the Blue Mountains have already claimed it. By the way did we mention our website, Luci has done a great job on it I think http://blackwattlemews.sydney/
And, finally in this long email, we have drafted our demonstration project justification which we would like to share with you next week. Any comments/improvements would be appreciated!