Sun-smart solutions on hotel-scale proportions
15 July, 2021
The Majestic M Suites Apartments in Tynte Street prove two things – that actively reducing overall energy consumption is as important as the energy source, and that solar power is just as viable for a larger accommodation provider as it is for homeowners.
The second of our two stories about our recent tour of this Carbon Neutral Adelaide partner’s newest development begins on the roof with owner John Culshaw. 330 north-facing solar panels equate to a seemingly standard grid-connected 99 kilowatt (kW) system.
When the power being exported to the grid reaches a certain level, the M Suites’ dual hot water system (a series of tanks with 15 kW elements) switches from gas to solar electricity. The system seeks to maximise the use of solar power to keep water heated, onsite, and to minimise electricity from the grid, and reduce gas consumption.
While the rooftop can fit more panels, John cites practicality for sizing the system. “There are a million things when it comes to power use – what source of energy, what decisions you make along the way. But managing the insulation qualities of the buildings from the outset and using less power is important. It isn’t always about just adding more panels.”
The ‘esky’ approach starts with a considered approach to air conditioning and minimising heat transfer with double-glazing (high-tech glass and argon vacuum) for all external windows and doors.
When it comes to electricity-use, there’s a whole range of smart controls and product choices. LED lighting with motion sensors and automatic timers are used throughout the hotel, including in rooms and stairwells. Spaces are not over lit and rather than using switches with lights built in; these are placed in intuitive spots on walls. Directional desk lighting, too, carefully calibrated to provide just the right of light to the workspace. This has the added advantage that at night there are no glowing lights to keep light-sensitive guests awake.
The engineer in John means improvements continue. In the underground carpark, a recent review of sensors (which adjust lumens for day or night conditions, and switch lights on and off only when cars are moving towards or out of the zone) is expected to save an additional $1,500 from the next quarterly power bill.
The result is impressive. As reported by John, the February 2021 power bill for the 12,000m2 M Suites was just over $5,000 for around 16,500 kWh electricity imported from the grid. This amazing result is around 32% of the power used for the Majestic Roof Garden Hotel over the same period, which has a smaller building area, and a slightly lower guest capacity of 238 compared to 246 guests.
M Suites is a great model for hotels and apartment developments of how thoughtful design and managing power after occupancy can translate into good financial savings and make significant reductions in the use of electricity from the grid.
Find out more about the Carbon Neutral Adelaide Partnership Program
99 kW Solar system on the roof of Majestic M Suites
Light sensors in the car park can be adjusted for maximum efficiency
Insulated tanks for water heating
Battery bank at Majestic M Suites