Best Grid-Connected Renewable System 2021

Joint Winner: Infinite Energy NZ for the Forest Lodge Orchard Project

Forest Lodge Orchard is a large-scale cherry orchard in Central Otago, that aims to produce a high quantities of food on 100% renewable energy. NZ is built on food production, and to meet NZ’s Zero Carbon legislation targets, we need to focus on bringing the carbon cost associated with food production right down.

Infinite Energy was tasked with designing scalable on-grid solution that allowed Forest Lodge to charge and operate a large amount of electrical machinery including irrigation pumps, NZs first electric frost fighting fans (made possible by a grant from EECA), a number of electric vehicles including NZ’s first electric tractor. Additionally, allowing intelligent energy storage and the ability to export back to the grid programmatically to limit congestion charges and provide another farm revenue stream through optimising export during times where the electricity market spot price is high.

Mike Casey, the owner/operator of Forest Lodge, has written a custom computer program running on a micro-computer that interfaces directly with Infinite Energy’s solution. Using a Ripple Control Unit, Forest Lodge can pick up on times of congestion and avoid Aurora congestion charges, as well as export and contribute back to the grid to help offset capital costs.

Last month (April) Forest Lodge’s total energy bill was $-100 (which might not seem like a lot) but considering previous power bills were getting close to $800, you can begin to see how quickly the pay back on this system is.

The long-term goal is not only to run with no fossil fuels, but actually to run the orchard entirely with zero overall energy costs and thus drastically bringing down the payback period of capital expenditure as well as prove to many other industries that reducing carbon is beneficial beyond pure altruism.

Watch the video: https://player.vimeo.com/video/540475077

More about Infinite Energy

Joint Winner: Vector Powersmart for the Watercare Floating Solar Farm

The challenge

Watercare has an operational carbon emissions-reduction target of 45% by 2030 and an energy neutrality target for its two largest wastewater treatment plants. The business wanted solutions that could help to achieve its emissions target and reduce the operational cost to serve its customers.

Watercare is conscious that with Auckland's population growth and land at a premium, any proposed solution would need to counter these challenges.

The product solution

Vector Powersmart presented an unsolicited unique and bespoke solution – a grid-tied, 1MW floating solar plant installed on 10,000m² of unusable real estate (the Auckland Rosedale wastewater treatment pond).

The advantages of this solution are to increase the value from a marginal land asset and enable the business to adapt efficiently and quickly to meet any future growth requirements by simply increasing the array size on the pond.

The outcome is that generation from the solar plant will supplement Watercare’s electricity demand from the grid and from biogas cogeneration that is already generated on-site from wastewater treatment. The electricity is used for pumping and aerating natural bacteria that help break down the waste as part of the treatment process. It achieves targeted electricity cost savings for Watercare and meets an estimated 25% of the grid electricity used by the Rosedale treatment plant.

The implementation

The first step was to construct the 1MW floating solar array on land in four quadrants using more than 2,500 panels and 4,000 floats. Each completed quadrant was constructed row by row and simultaneously lowered into the pond via a purpose-built ramp and pulley system. The completed portions of the array were then towed and fixed by two vessels to 62 permanent mooring anchors that were positioned using precise GPS coordinates.

The entire array was connected using purpose-built floating walkways and Vector Powersmart's floating cable management design, to the 16 ground mounted inverters and custom solar switchboard enclosure installed on the land adjacent to the pond.

Technical specifications

Size: 1.04 MWp over 10,000+m²
Solar Panels: JA Solar 380W Monocrystalline (2,736 modules)
Mounting: Ciel et Terre Modular Floating System (4,000 floats) and bespoke mooring anchors (62)
Cable Management: VPS floating cable management system
Solar Switch Board & Inverters: Custom solar switch board enclosure system and ground mounted SMA Core1 - 50kW (16 units) and SMA data manager monitoring system (1 unit)