Solar makes sense in sunny Central
A Central Otago winery has switched to generating its own solar power, as part of its commitment to environmental stewardship.
The north-facing roof of Felton Road’s winery in Bannockburn has been transformed to a power plant with the installation of a 118-panel solar photovoltaic (PV) array.
The 32-kilowatt solar array designed and installed by Sunergy Solar, is expected to supplement approximately 50 percent of the winery’s daily energy needs in mid-summer.
“The winery’s primary power load is cooling and refrigeration in the winery and wine cellars, and running the ofﬁces” says Blair Walter, winemaker at Felton Road.
“What’s interesting for us is the peak solar generation completely matches our peak summer load for refrigeration in the cellars and wine storage.
“It’s exactly on those days when its completely sunny and the sun is out for long periods of the day that we have our peak usage.”
“We looked at solar power 15 years ago, but the cost of solar panels wasn’t feasible, but nowadays, with a return on investment of around 10% for Felton Road, it makes a very sound business case.
“The system was designed to give a ROI (return on investment) of 8.9%, and this is before depreciation is taken into account.
It also does not take into account the additional savings we can achieve with the introduction of further electrical controls with our cellar cooling.”
Andy Wells, managing director at Sunergy Solar points out, “your return on investment (ROI) is linked to the price you’re paying for energy. If your energy costs increase, your ROI also increases.”
He said that most of Sunergy Solar’s commercial and agricultural customers are achieving annual returns of 15 to 20%. Once all ﬁnancial beneﬁts are accounted for, the payback period is expected to be around eight years, after which all of the power generated by the solar system will be free for the life of the system.
Solar panels are warrantied for 25 to 30 years, but in New Zealand’s mild climate they could be expected to still be operating after 40 or 50 years, said Wells.
At Felton Road the Austrian-made Fronius inverter is connected to the internet and provides accurate monitoring of both the solar production and the energy demand of the winery.
This information is accessible via an application on Walter’s phone or computer, allowing him to remotely monitor and manage the power production and usage within the winery any time.
He can take advantage of times of day when excess power is being generated by the system, and rather than exporting back to the grid he can tweak the system to do extra cooling in the winery.
“We can cool more during the day when the electricity is being generated and essentially the cellars, with their large thermal mass of barrels ﬁlled with wine, are operating like batteries, storing energy into the evenings,” says Blair.
“Modern technologies in thermostats and timing equipment make this all possible.” In winter, and on cloudy days, the system still generates electricity, just not as much as on a clear sunny summer’s day.
During night-time and any time of the day when there is not enough power generated by the panels, electricity from the grid tops up the supply. Any excess power generated by the system is supplied back to the grid, and Felton Road has negotiated a buy-back rate with their local community-owned power company, Pioneer Energy.
Blair says while some other bigger New Zealand wineries, such as Yealands and Spy Valley in Marlborough, had generated their own solar power for some time, he believed this was the ﬁrst solar array of signiﬁcant size to be installed in a Central Otago winery.
He expected other Central Otago wineries would be looking closely at their own businesses as power costs rise and environmental beneﬁts of solar power become more attractive.
“Solar power does take ﬁnancial commitment but as our businesses are growing and settling down, we can start to make these steps.”
This article was brought to you in association with the following businesses…
- Sangster (Duncan) Electrical
- Specialised Heating & Refrigeration Ltd
- Sunergy Solar