Alongside wind power, solar has been touted as the ideal endgame for renewable energy, but the hype continues to outpace reality, with the market relying on low-deposit or no-deposit finance plans to lift it from the slump of stalled prices.

Transpower, in analysing future scenarios based on falling costs, improved efficiency and advances in areas such as nanotechnology, predicts a rapid increase in solar, with 58-69% of homes and 25-40% of businesses having systems by 2050.

By that stage the government-owned national power grid operator predicts solar will be slightly cheaper than gas and wind.

The Sun Rises on a Solar Energy Future, the update to its 2018 Te Mauri Hiko energy futures report, has been called a game changer, encouraging distributed and utility scale, battery-backed solar generation.

Without a change in attitude from the electricity industry, the provision of government subsidies or incentives, or a drastic shift in affordability and return on investment (ROI), the solar revolution will struggle to radiate the numbers touted by blue sky visions and alternative energy advocates.

Although the cost of a 10 panel 3kW system has dropped dramatically since 2008, that’s levelled off in the past three years to around $9,000, or nearly double that with a battery, according to SolarQuotes. 

Westpac agrees the price of domestic 3kW systems has “flat-lined” as it points homeowners to the value solar adds to house prices, rather than immediate power savings or ROI which isn’t exactly compelling.

Payback time

Sustainable Energy Association of New Zealand (SEANZ) director Kristy Hoare says a domestic solar system will generate between 10 to 12% ROI through energy bills in the first year, improving as electricity costs rise around 4% annually, with payback typically 8-10 years. 

Meanwhile, the hype continues, with regular announcements of improved efficiency, storage, design and materials, promising everything from solar compatible paint and roading material to wearable solar tech or tiny panels stitched into clothing, window curtains or car seats. 

Innovations fresh from science labs and commercial trials continue to tweak what can be done with photovoltaics (PV) which capture sunlight to generate electricity, and concentrated solar power (CSP) that harnesses the sun’s heat for thermal heating and turbine energy. 

Stretching the imagination in the PV camp are solar-powered roads and footpaths, already tested on a section of Route 66 in the US, where the thermal capacity can melt snow and light the way with LED bulbs. 

Michigan State University researchers claim their see-through panels create huge possibilities in architecture, mobile electronics and the automotive industry. The transparent luminescent solar concentrator (TLSC) based on organic molecules can be placed over any clear surface, although efficiency needs a serious boost.

MIT researchers have doubled the efficiency of solar cells by capturing waste heat from panels, delivering improved cost and efficiency per watt.

Solar tracking mounts that tilt and shift ground-based panels so they follow the sun are in big demand, with a claim half of US arrays will go that way by 2021.

Storing it up

Late last year the NZ Productivity Commission and Vector released reports claiming solar and batteries would play an important role in New Zealand’s clean-energy future. 

While slowly becoming more efficient and affordable, solar batteries remain a big part of the cost of a system, $8,000-$11,000 for 6.5-10kWh options which, without high sunlight hours, still need a grid recharge.

According to industry sources there were 20,712 solar systems across New Zealand by late 2018 and by January this year 90 were larger 1 MW systems.

SEANZ claims one new solar PV system is installed every 25 minutes and 30% of households with a solar system have battery storage, up from 16% in 2016.

Many of the big electricity retailers have joined the specialist installers, offering solar systems and batteries including Tesla Powerwall, LG Chem and Panasonic models. 

From May, Sonnen batteries from a former Holden factory in South Australia were being distributed by Taspac Energy. They restore power quickly in the event of a mains blackout or natural disaster and can be recharged through solar panels without a grid connection.

However, current lithium-ion storage batteries can present a fire hazard and with a life of 5-15-years there are end-of-life disposal issues that no one has quite got their heads around.

Bottled heat?

Alternatives may include solar thermal fuel (STF) or bottled heat batteries that store energy as a charge. 

University of Massachusetts scientists have devised a plastic-like polymer, AzoPMA that absorbs sunlight in a high energy state, while Chalmers University of Technology in Sweden is developing the Molecular Solar Thermal Energy Storage (MOST) system.

MOST collects and stores sunlight through a special fluid that can release its heat in a continual reusable loop when passed over a catalyst.

Science tells us there are multiple ways to use the sun’s energy for heat and electricity, although Kristin Gillies, former Hawke’s Bay resident and communications manager with SEANZ, suggests many of these are far from commercial reality.

While it’s “exciting stuff that generates media” few are likely to make it to New Zealand in the short-term. The only innovation that’s challenging PV panels is the trend toward solar roofing tiles. 

What’s needed to revitalise our solar industry, he suggests, is more developers and building companies creating solar houses or solar-ready sub-divisions. 

“You have to think of the life of your house and how much things are going to change over that time … Deciding to retro-fit later is a heck of a lot more expensive,” says Gillies. 

Optimal positioning 

Many factors need to be taken into account before committing to solar, including the need for north-facing roof space in high-sunlight areas.

Misinformation, skewed sales pitches and uninformed purchases have left some homeowners feeling burnt. One solar signatory felt they’d been left with little more than a fancy roof decoration when the finance costs overshadowed the promised savings on their power bill. 

Gillies says most complaints come from those who do nothing but put panels on the roof, are not daylight power users, or expect to be reimbursed by selling energy back to the grid.

Many were turned off solar when distributors and resellers collectively reduced their solar buy-back rates. What’s needed he says, is a “behavioural change and better use of … simple tools that mean you don’t have to export to the grid.”

He suggests a seven year ROI is possible with a home energy-management system that assesses how much energy is generated then distributes the load where it’s most needed. 

Timing is important

The key is using timers, now standard on new dishwashers and washing machines, and to run appliances during daylight hours even if you aren’t at home. Add-on timers can achieve this for older models.

Once the clothes and dishes are washed, a diverter can channel surplus energy into your hot water cylinder, which makes up about 25% of most power bills, rather than exporting that power at low rates. 

He recommends an assessment from a SEANZ member and using its online solar ‘optimiser’ to recommend a system configuration based on time of use and expected payback. 

SEANZ was among the solar lobbyists who challenged the accuracy of the Government’s Energy Efficiency and Conservation Authority (EECA) online calculator and its ‘not yet’ line on solar ROI. 

The calculator developed by Canterbury University as part of $6 million renewable energy research funding was taken offline in April after the pro-solar camp claimed it was skewing the data.

Rent-to-own options

Efforts to ease homeowners and businesses into solar include ‘rent to buy’ plans or zero upfront costs for panels, battery and management systems.

A long-term commitment, up to 20 years, will allegedly deliver a fixed power bill with 10-15% savings or around $300 in the first year and around $20,000 over 20 years. Panel manufacturers typically offer a 25-year warranty, but advise an annual soapy water wash to maintain performance.

On selling the house the purchaser can pay what’s owed or take over the finance, or the seller can move the panels and battery to their new house. 

First Light House, Waimarama

The growth of solar is tied to ongoing challenges for electricity distributors like Hawke’s Bay’s Unison and its retailers, who are modifying traditional charging models to reflect the often erratic demands from solar systems and EVs.

Every solar connection into Unison’s network pays a $100 fee plus a ‘solar tax’ of 24-26 cents per kWh (kilowatt hour) and is offered a buy-back rate of 7-8 cents kWh.

Unison and its retailers charge by capacity or time of use (TOU) kilowatt per hour charges ($/kWh) and providers are looking at ways to reward solar and EV owners who use timers and off-peak recharging.

There may be around 100 off-the-grid systems (not including those that power rural pumps and electric fences) and around 1,100 grid-connected systems, including 50 or so commercial, industrial and school connections, an area that is now growing faster than the domestic market.

The so-called ‘solar tax’ is expected to be withdrawn by April 2020 when the new pricing regime is cemented.

Unison’s ideal scenario is 30% of users taking 30% solar by 2030 (30/30/30). The company believes two-thirds of recent solar installations are on some form of financial or lease package with most including batteries.

Peer pressure

A growing challenge will come from peer-to-peer (P2P) solar. Kaitaia College went live with a 368-panel rooftop system in February using Trustpower’s Solar Buddies programmes to gift or sell excess electricity to any household served by the same retailer.

The school expects to save tens of thousands of dollars over the 10-year payback period. 

Gillies says this approach has the potential to create a secondary market with businesses and households generating, storing and sharing excess with their neighbours or friends.

A proposal to establish a ‘mega solar farm’ serving residents of Flaxmere and Camberley is currently before Hawke’s Bay Regional Council (HBRC) and potential funders.

St Andrew’s Presbyterian Church in Hastings wants to build the 1MW PV solar farm with up to 4,000 panels on two hectares of land near Flaxmere at a cost of around $2.7 million.

The Power to the People (PttP) project is a response to concerns that tenants in many rental homes are ‘energy poor’, or spending 10% or more of household income on energy. 

They typically use 20% less electricity than the average New Zealander because they rug up or get into sleeping bags in winter to reduce power bills, risking sickness and unemployment.

The church claims it can deliver electricity to around 1,500 people in 400 low-income homes at 25% below mainstream prices; 45% would come from the PV solar farm, the balance from the wholesale market.

The project is supported in principal by Unison and Hastings District Council. HBRC has been asked to lend $500,000 through its Sustainable Home Programme, to be repaid over ten years. Pre-requisite grant fundraising is now underway. 

Business takes lead

Large commercial businesses are part of solar’s growth curve, with high daytime use and attractive finance plans now stacking up economically.

Misco Joinery in Kaiapoi adopted sunshine energy in May with a 153kW system of 535 solar panels providing 65% of its energy consumption with ROI of 16%. 

Other recently activated systems include Comvita (300kW), Zespri headquarters (61kW), a couple of Mainfreight Distribution centres, numerous warehouses, resorts, supermarkets, schools, petrol stations and businesses, including several large 1MW solar farms under non-disclosure.

Solar farms are commonplace in many parts of the world. In Germany they’re part of a plan to replace nuclear generation and China has vast acreages, including farms shaped like giant pandas — Panda farms — aimed at replacing the need to burn millions of tons of coal.

Sometimes though there’s a need to start small and learn, perhaps like the Flaxmere farm or Tony Krzyzewski’s small passive 50kW solar farm heating his swimming pool in the winegrowing community in Bridge Pa.

While it works wonders on sunny days, other than the purely philosophical stance of wanting to save the planet, Krzyzewski hasn’t seen any ROI on the PV panels, batteries, cost of installation, technology and line charges. 

“If the price of power jumps, the price the grid is willing to buy-back increases, or the cost of panels and batteries comes down, then there may be a crossover point, but I don’t think that it is there yet.”

To encourage large solar farms in Hawke’s Bay, with land so valued for agriculture and horticulture and indeed housing, a robust business case would be needed along with answers to questions like: what happens on sunless days; would solar glare blindside drivers, or would solar installations be uglier than a zig zag scar on Te Mata Peak? 

The solar challenges remain. If new homes come broadband-ready, why wouldn’t they also be solar-ready with capacity for charging an electric vehicle (EV)? 

Do we need local and central government incentives to push more aggressively to reach Transpower’s 2050 projections? Will Greenpeace get traction on its petition to repurpose oil and gas industry subsidies for solar on 500,000 New Zealand homes by 2030? Or, in a country already generating more than 80% of its electricity from renewable sources, do we simply await improving market rewards? 

Unison is pleased to sponsor robust examination of energy issues in Hawke’s Bay. This reporting is prepared by BayBuzz. Any editorial views expressed are those of the BayBuzz team and do not reflect the views of Unison.

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