Kids’ brains are fantastic little things, able to gobble up nourishing information as quickly as their owners’ stomachs will process pies and ice-cream. Lucky they can take in so much, because when they hit school children’s noggins are pitted against an onslaught of learning. Under the right conditions most of them take it in their stride and graduate to the next level in life: work.
Under the wrong conditions, however, learning is a far harder task. Any teacher will tell you it’s pretty much impossible to get the message across about algebra in an airless classroom heated to boiling point by the afternoon sun.
“The environment you learn in is absolutely critical in determining how well you will learn,” says David Wrench, executive director of Hivve, a Sydney-based company that creates sustainable classrooms and energy solutions for schools. “Classrooms that have no air-conditioning or any type of ventilation systems can be pretty awful.”
Energy hungry
Schools are using more energy, Wrench says, as student numbers rise and ever more equipment is installed to back-up the curriculum. Meanwhile, the education system’s built environment is ageing and may be woefully inefficient. It’s getting to the point where older schools are running into grid energy constraints, Wrench says, forcing them into a corner where they have to invest just to carry on. “To upgrade power supply is a very significant capital cost.”
Hivve’s solution is to introduce self-generated power is an alternative energy source, so a school can operate within its grid connection constraints and slowly minimise the energy needed from the grid. “It gives schools the ability to manage their energy infrastructure without slavishly going to their networks and saying, I want an upgrade.”
The answer, of course, includes solar PV, and Hivve recently completed a pilot trial of three of its demountable classrooms at St Christopher’s Catholic Primary School in Holsworthy in Sydney and at Dapto High School in Dapto, NSW, to measure the energy balance and how the indoor environment could be maintained at high quality levels for teaching and learning while using minimal energy.
Load reversal
A regular classroom can consume about 3,800KWh a year, but a HIVVE classroom with solar PV, battery storage and the company’s proprietary energy management system generates about 7,600KWh a year.
That result, where one classroom can power itself and two others, is conservative, Wrench says. Network-connected classrooms pretty consistently generate “five or six times” what they use.
“Most of the time it’s powering itself and exporting energy and offsetting other energy demand in the school network,” he says. “We’ve demonstrated the concept works very well and are now able to show it works equally well in existing older classrooms. We’ve moved on to delivering power control systems to help schools in total move towards energy self-sufficiency.”
It’s no surprise one of the biggest drains on energy in schools is air-conditioning. “The way you manage air-conditioning and temperature and ventilation control is absolutely critical to energy demand,” he says. “If you do it well it can be incredibly efficient but most schools don’t have the ability to manage and control their air-conditioning well and there is a massive amount of energy that is being wasted.” Haphazard installation of incremental new air-con units may only compound the problem.
In control
To make an impact in schools you must do two things: focus on renewable generation and link that to energy demand control. “You need to do both, because that’s really the way you improve a school’s energy efficiency and energy self-sufficiency,” Wrench says. “You also create a stable, comfortable, good-quality environment for the students and teachers to operate in. That’s really the fundamental driver.”
The Hivve classrooms are built for thermal efficiency, balanced against a requirement for plenty of natural light – a positive from a learning perspective but a little bit of a negative from a thermal efficiency perspective.
Natural timber lining allows for a more welcoming, warmer feel than a typical sterile environment. The combination of design and materials has resulted in what Wrench describes as an “acoustically pleasant space”.
Whiteboard to dashboard
The teacher knows best, of course, which is why the adult in the room is allowed to fiddle with the controls after checking a dashboard which shows temperature, air quality, external temperature, energy generated and energy use. “That information enables the teacher and the students to really understand how they need to respond to changing external environments, changing energy demand and managing that,” Wrench says. “The control is in the hands of the users of the room.”
A couple of classrooms are also operating off the grid, where air-con is controlled automatically to avoid human overindulgence or error. “In those classrooms the teacher does nothing. That’s been very successful,” he says. “Not having to worry about mucking around with the environment is a great thing for teachers. It takes up an inordinate amount of time in classrooms getting things right. Then you can just get on with teaching.”
Off-grid classrooms featuring solar and storage in Brackenridge, Queensland, and in Dapto haven’t missed a beat, he says. “They’ve been fabulous.”
The day after tomorrow
With the pilot program successfully ticked off, thanks in part to $368,000 in funding from ARENA, Hivve is moving into commercialisation phase, building classrooms in South Australia and NSW and retrofitting existing classrooms with the Hivve technology.
The next phase is an integrated power supply system, where Hivve is working on supplying power to an entire secondary campus in a primary school, using solar with battery storage and a Hivve control system that will power the entire new section of the school.
The only time the battery is needed materially is winter mornings, he says, before the solar kicks in. “We’ve never really seen battery storage levels get much below 60%, even with fairly extended periods of overcast conditions.”
The buildings perform best of all in summer, when solar energy is at its strongest; the battery is most relied on during winter mornings, when there is a heat load on the building and the solar generation window is slow to open.
On holidays and weekends if the battery is charged and there is no load, the solar is disabled.
The shift into offering energy solutions is part of a long-term strategy. “It’s not about just whacking on some solar and batteries and doing a bit of monitoring; [it’s about an] intelligently designed system that is delivering an environment [to learn in],” he says. “Your performance criterion is the environment you end up with … and what is the most cost-effective energy-efficient way to achieve that, and trying to achieve that supply using renewable energy to the greatest extent possible.”
That wasn’t the objective when the company started out 40 years ago. “It’s been quite an exciting progression.”
And in case you were wondering, it’s Hivve as in beehive. “Beehives are phenomenally well climate-controlled,” Wrench says. “The thermal control the bees have is incredible.”