Rooftop Solar

Single-axis trackers on commercial rooftops increase generation by 37%

Image: Alion Energy

Alion Energy trackers thread the return-on-investment needle with productivity gains from white roofs and bifacial modules, while design aggressively maximizes module count.

From pv magazine USA

Alion Energy’s single-axis tracker racking product was originally designed to be deployed in regions where heavy installation equipment was more challenging to access, but labor might be more available.

One aspect of this design philosophy is that the system is light and can be easily carried and assembled, and doesn’t require metal pilings to be driven deep into the ground. And interestingly, this carries over to commercial rooftops.

Mark Kingsley, Alion Energy CEO, said in a post on LinkedIn that a commercial real estate group had installed a standard rooftop, 10-degree fixed tilt monofacial solar array, as well as a competing Alion Energy system.

The results were as expected – 37.5% greater generation on a per watt basis from the single-axis tracker, on a pristine white thermoplastic roof versus standard modules. Of course, the real breakthrough is that they were able to get single-axis trackers installed on a commercial rooftop at all.

The rooftop in their example has a lot of skylights, and the overall structure is not facing due south. In this configuration, Alion Energy suggests that it can fit 4.55 MW of modules on the Maryland structure with a standard 10-degree installation. This system is projected to generate 1.34 kWh per watt each year.

Alion has designed a system that is 5.4 MW – a full 18% increase in wattage due to systems ability to be installed directly over skylights without needing the standard setback. Additionally, this hardware is projected to generate 1.54 kWh per watt installed per year.

In this case, that works out to 37% more electricity from the same rooftop. And when the trackers are directly attached to the roof – a 2.15 pounds per square foot dead load. Add in one Alion’s customized robotic cleaners, and the company says the levelized cost of electricity from the system falls to 4.67¢/kWh and generates 40% more electricity than a standard rooftop solar install.

And while this rooftop was selected to show off their hardware, it’s still an interesting best case scenario for us to consider.

Author: John Fitzgerald Weaver

Melbourne’s suburbs shining with solar and battery uptake

Solar suburbs in Victoria. Image: Solar Victoria

After a bumpy start, the Victorian government’s Solar Homes Program is now in full swing, lead by strong uptake in Melbourne’s suburbs and the state’s rural north. Meanwhile, demand for batteries linked to rooftop solar has skyrocketed over the last month, spurred by the energy crisis and an especially cold winter.

From pv magazine Australia

The Victorian government’s $1.3 billion Solar Homes Program (program) may have had bumpy beginnings but it’s certainly up and running now, not only boosting solar uptake but also virtual power plants (VPPs) and residential batteries. 

Melbourne’s outer suburbs are leading household solar boom. Since the rebate began back in 2018, five metropolitan suburbs have accessed more solar rebates than any others. Indeed, Tarneit, Cragieburn, Point Cook, Clyde North and Truganina make up a full 10% of all Solar Homes installations across the state. 

Rural access to the Solar Homes program was a point of criticism for Nationals’ Victoria Murray Plains MP Peter Walsh in 2020, who alleged Melbourne-centrism in the program when his electorate was overlooked by the program’s scheme for energy storage devices. 

However, northern Victoria is leading the uptake among rural areas of the state, notably the regional cities of Mildura, Shepparton, Wodonga, Wangaratta and Wallan. 

The Victorian government claims the program has already helped more than 200,000 Victorians install solar, saving households an average of $1,073 on their annual electrical bill. Moreover, a Solar Victoria customer survey revealed that 71% of respondents would not have installed solar if it hadn’t been for the program. 

“Our Solar Homes Program is driving down the cost of living for Victorian households and reducing emissions,” says minister for Solar Homes Lily D’Ambrosio. 

“Solar Homes customers are well-positioned to absorb energy bill rises in energy costs, by time-setting appliances to run during the day when solar systems are operating at their peak.”

The program is still open, and Victorian homeowners and rental providers are able to apply for rebates of $1,400 for the installation of solar panels, with an optional interest free $1,400 loan, and a further $1,000 rebate for the installation of solar hot water.  

“Household solar puts the power back into the hands of Victorian households,” continued D’Ambrosio, “while helping meet our target of halving emissions by 2030 and supporting 5,500 clean energy jobs.” 

Battery boom 

The last month has seen especially cold temperatures which, in combination with the energy crisis, has seen the demand for solar battery energy storage systems skyrocket. Solar Victoria chief executive, Stan Krpan, told The Guardian that inquiries into battery rebates in Victoria have spiked in the last two weeks.

Rates for residential battery energy storage systems are also available to households that have not previously claimed a Solar Homes rebate. The Andrews government expanded the scheme in March, and it now offers up to $3,500 for households to install a solar battery. 

Krpan reported that 5,842 battery rebate applications have been approved this financial year, more than double the number received last year with three weeks still to go. “In the past two weeks, phone inquiries to our contact centre have been 50% higher than the yearly average,” said Krpan. “We’re expecting this to lead to growth in installations over the winter months.”

The Victorian government-backed is also now supporting six different two-year VPP pilots as part of its Solar Homes program. The program is capped at 2000 rebates with the state government saying households that sign up to the pilot prior to June 30, 2022 and install a battery will receive a rebate of $4,174.

It has approved five battery brands to participate in the six distinct VPPs which it says will give participants “guaranteed financial benefits and additional consumer protections not widely available in the general market.”

The program’s five approved battery providers include Tesla, Mondo, Reposit, Sonnen and Arcstream.

Author: Blake Matich

Open-source software to identify best locations for PV projects in urban areas

Roof Segmentation: (a) Select the urban area of interest, (b) LiDAR 3D model with roof segmentation, (c) Normalized roof heights model. Image: University of Malaga, Expert System with Applications, Creative Commons License CC BY 4.0

The proposed methodology relies on geographic information and meteorological data. Project developers can use it to evaluate the potential energy production by a photovoltaic system for either a long or short time.

From pv magazine

Researchers from the University of Malaga in Spain have developed an open-source software platform based on a data mining process that they claim can help decision making in identifying locations for photovoltaic projects in cities.

Through the proposed methodology, which relies on geographic information and meteorological data, project developers should be able to evaluate the potential energy production by a photovoltaic system for either a long or short time.

“The system accesses the geographic information that was previously downloaded and creates a map with a grid that delimits the areas available for energy estimation. It allows the user to select the area of interest by defining a polygon on the map,” the scientists explained. “The system then loads the image covering the area delimited by the user’s coordinates through the polygon on the map. Subsequent processing steps only take into account the data filtered in this step.”

The software integrates data on the mean inclination, orientation, size, and latitude for every connected component. It also implements an image processing model and extraction of the characteristics of the roofs, as well as photovoltaic energy calculation models.

“This tool offers excellent opportunities because it can be easily updated with new features made by the same developers or new contributors. After all, the source code is released,” the academics explained. “Those new features could include focusing on new types of elements in a city or performing a more precise estimation of the energy potential.”

The scientists presented the software in the study Data driven tools to assess the location of photovoltaic facilities in urban areas, which was recently published in Expert Systems with Applications. “URSUS-PV is offered as a free web tool available to individuals, municipalities, neighborhood communities or companies in the photovoltaic sector,” the research team said. “It is also supplied as a package that can be altered to be adapted to specific scenarios or improved with new features.”

Author: Emiliano Bellini

Program ‘switching’ concession payments for solar systems to be expanded

Source: Worksafe Victoria

From pv magazine Australia

South Australia will extend its ‘Switch for Solar’ program in which eligible low-income residents can opt to have a solar system installed in exchange for their next ten years of government concession payments.

The South Australian government has announced it will expand its ‘Switch for Solar’ program, opening up another 5,000 spots for residents on either an eligible Centrelink payment, who meet low income provisions, or hold an eligible concession card.

Program participants will be able to install a 4.4 kW solar system at no upfront cost in return for their annual Energy and Cost of Living concession payments over the course of a decade.

The program was initially piloted in May 2021, opening to 1,000 eligible residents. The state government described this initial pilot phase as “highly successful”, saying the program now has “proven results”.

“Electricity bills of households already in the program have fallen by well over $1000 a year resulting in a net benefit of up to an average of $538 for these low-income households,” Deputy Premier Dan van Holst Pellekaan said.

Concession holders in the state receive up to $215.10 per year from the Cost of Living Concession and up to $231.41 per year towards their energy bill, totalling up to $446.51. Swapping this payment for a decade would mean the government recovers a total of $4,460 for the solar system.

Data from the pilot trial found concession households who “switch” their total concession payment for the solar system receive an average of $538 in savings over and above their existing $446.51 saving from their concessions. This is higher than the initial estimate of $57 to $525 when the scheme was launched, the government said. 

“Around 28% of households so far have opted to co-contribute to get an ever bigger solar system and even bigger bill savings,” Pellekaan added.

“This innovative more than doubles the bill savings we deliver to concession households, through solar instead of cash payments, with strong safeguards for participants.”

South Australian concession holders will now be invited to register their interest in the program with the 5,000 systems to be rolled out from August 2022.

Author: Bella Peacock


Australia passes 25GW of installed PV

Source: Australian PV Institute

From pv magazine Australia

Australia has hit a historic milestone – it has reached 25GW of installed solar capacity. As the Australian PV Institute noted on Monday, that’s more solar per capita than anywhere else in the world.

With a population of about 25 million, Australia now has nearly 1kW of PV installed per person – easily retaining its world-leading status.

By the end of 2021, there were more than 3.04 million PV installations in Australia, with a combined capacity of over 25.3GW, the Australian PV Institute noted.

Australia’s solar market has gone through surging periods of growth since the government’s Renewable Energy Target (RET) scheme commenced on April 1, 2001. Between 2001 and 2010, the solar market’s growth sat around 15%, before a period of far more rapid growth from 2010 to 2013.

After stabilizing between 2014 and 2015, the market is trending upwards, driven by residential installations. Rooftop solar today plays an important role in Australia’s energy mix, contributing 7.9% to the National Electricity Market (NEM) demand in 2021, up from 6.4% in 2020 and 5.2% in 2019.

According to figures published by the Climate Council in February, renewable energy generation in the National Electricity Market increased by almost 20% in 2021, with renewables supplying 31.4% of electricity generation last year.

In South Australia, these percentages are far more staggering. In the final days of 2021, the state ran for almost one week on renewable energy. South Australia’s 156-hour stint powered by wind, rooftop solar and utility-scale solar farms, firmed by fractional amounts of gas, was considered record-breaking for comparable grids around the world.

Percentage of dwellings with PV
Source: Australian PV Institute

Author: Bella Peacock