How solar plants should keep an eye on glint and glare

With more solar farms likely to be constructed near towns and settlements, developers will have to carefully consider the impact of glint and glare from photovoltaic (PV) panels before they proceed.

Global experience shows that sunlight reflecting off solar panels can cause annoying visual discomfort and even hazardous glare to surrounding receptors such as residents, motorists or pilots. Sunlight reflecting off solar panels can be experienced in two forms: glint which is a momentary flash of bright light; and glare – a continuous source of bright light. Both glint and glare can result in an after-image, which is a visual illusion where an image persists after exposure to the original image has ceased.

Motorists passing by may be affected, for instance, posing a potential traffic hazard – while nearby communities could be disturbed by sunlight reflections. Recent changes to the licensing regulations for Independent Power Producers have opened the door for private renewable energy projects up to 100MW. While most commercial solar projects to date have been located in remote areas, these developments may now be increasingly located closer to urban areas, according to Chris Dalgliesh, partner and principal consultant at SRK Consulting.

“We have seen a few solar projects being established fairly close to towns, and there will be more of these to come,” says Dalgliesh. “This increases the likelihood of glint and glare impacting more often on human settlements and other receptors.”

Sue Reuther, partner and principal consultant at SRK Consulting, highlights that while there was generally a high level of public support for renewable energy projects, the growth of solar farms had shown that glint and glare could be significant visual impacts. As such, these aspects have become an essential component of Visual Impact Assessments (VIAs) that SRK Consulting conducts for Environmental Impact Assessments (EIAs).

Kelly Armstrong, environmental consultant at SRK Consulting and a specialist in modelling visual impacts, says that developers need accurate, science-based predictions on how their solar installations might affect the local environment.

“A range of parameters are loaded into glint and glare modelling software to assess whether the glint or glare from solar panels will impair vision or cause discomfort,” says Armstrong. “This includes the project’s precise location, local topography and the height of the mounted panels – as well as the axes and aspect of PV arrays.”

The exact longitude and latitude determine the position of the sun across the seasons, allowing the model to account for the aspect of the sun on each day of the year. This is significant in measuring not just the occurrence of glint or glare, but to quantify exposure (minutes per day) to this impact.

Photovoltaic panels in a solar energy installation can be fixed or can rotate on a single- or double-axis, she notes. The model requires specific parameters of the proposed PV array inter alia the panels’ maximum tracking angle, resting angle and whether backtracking technology is used.

The position of the receptors relative to the solar energy installation is also critical. Typical receptors could include buildings, homes, roads and flight paths, with dozens of different points around the project all having to be assessed to understand the potential impact. Topography is important, as elevated areas around a solar farm could be more exposed to glint and glare. Dalgliesh notes that a viewshed is typically a vital component of visual impact assessments, and shows those areas (receptors) from which the solar farm would be visible.

“This spatial map guides our understanding of who or what will be visually affected by a development,” he said. “We can then identify those receptors which are likely to be most sensitive to visual impacts – including glint and glare.”

Both glint and glare can result in an after-image, which is a visual illusion where an image persists after exposure to the original image has ceased (Image: SRK Consulting)

The outcome of the modelling, explains Armstrong, is to accurately predict the exposure and duration of glint and glare impacts down to the minute each day – for each key receptor.

“The accuracy of these models allows us to report very detailed glare results,” she says. “For example, we can predict that a particular receptor would experience glare for a maximum of 15 minutes between 4.30 and 6.30 pm during the summer months.”

This provides the basis for strategic decisions, either on the precise location or orientation of the solar farm, or on appropriate mitigation measures. While there are currently no legally specified thresholds for glint and glare, she pointed out that there are international best practice guidelines to follow.

“These guidelines incorporate tolerable exposure thresholds, viz.  maximum 60 minutes per day, for more than three months of the year, above which mitigation measures must be implemented” she explains. “Our reports include mitigation measures, aiming to avoid any glare affecting receptors.”

Reuther highlighted that, as a leader in the field of EIAs, SRK is among only a few consultancies with advanced in-house expertise in glint and glare modelling – a niche likely to be in growing demand.

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Pandemic, climate change raise stakes for South Africa

In the face of Covid-19, climate change and growing economic hardship in South Africa, disaster risk reduction (DRR) should be a priority for government at all levels; the signs are, though, that there is still insufficient capacity and commitment to carry through on this mandate.

According to Martin Stols, principal consultant in GIS and disaster management at SRK Consulting, the Covid-19 pandemic has been a stark reminder of the importance of being prepared for unexpected events. It also demonstrated that certain risks are often underestimated, and that there is no room for complacency.

“The top priority hazards that we identified in disaster management plans in 2019 were fire, floods and drought, while human disease was ranked 14th,” said Stols. “The Covid-19 pandemic certainly would have changed this perception – but importantly it taught us how different sectors are impacted during a disaster and how interdependent many sectors are during a disaster.”

In this sense, DRR is everybody’s business, so it is vital to avoid taking a ‘silo’ approach when planning for and responding to disaster risk.

Integrated approach

“No single entity can ‘own’ or take sole responsibility for a hazard or disaster,” he emphasised. “There is sometimes a misconception that certain departments are responsible for a certain category of hazard – but there are always knock-on effects that extend well beyond the core impacts.”

For example, he noted that the Department of Forestry, Fisheries and the Environment (DFFE) may have a programme like Working on Fire, but the effects of a fire may require intervention by other departments such as Human Settlements and or Agriculture. Similarly, floods are not only the problem of the Department of Water and Sanitation.

On different levels of government there could be different agencies involved in the disaster continuum. For example, flood mitigation in a city environment will most likely be the responsibility of the roads and stormwater department, but the response efforts should there be a flooding event will lie with the emergency services.

“Disasters frequently demand more from government agencies than their direct mandate suggests,” he said. “The DFFE has a clear mandate to protect the environment, for instance, but when the Covid-19 hard lockdown led to the closure of the county’s national parks, many households around these parks needed emergency assistance. They were stripped of their primary source of income through tourism-related activities, and this led to the DFFE having to support these communities by providing food parcels and monetary support.”

He highlighted that disaster risk involves various factors, and can often be most effectively addressed by reducing vulnerability and improving capacity or resilience – a role which includes the responsibilities of a number of departments and sectors other than the department dealing directly with the hazard.

“This also means that better communication is needed among the different stakeholders, through participation in disaster management forums already established,” he said.

Institutional basis

Progress can only be made when DRR is mainstreamed into the operations of government, he urged. This requires – first and foremost – that DRR is well grounded, or institutionalised, within each department or agency. In practical terms, this means having the required policies and interventions in place, as well as organisational structures and cultures in support of DRR within each development intervention.

Stols noted that disaster management planning was already required by law, but that there were high levels of non-compliance. South Africa’s Disaster Management Act of 2015 demands that each national organ of state must conduct a disaster risk assessment for its functional area, map these threats, and prepare a disaster management plan (DMP). Many national departments, however, have not submitted DMPs to the National Disaster Management Centre (NDMC), as the law requires.

This presents a significant challenge to the national DRR effort, as the NDMC is mandated to make these plans available to provincial and municipal disaster management centres. The law also mandates the departments to coordinate and align their DMPs with other stakeholders, and to invest in DRR. Without full compliance at the national level, the roll-out of disaster management to other levels of government inevitably becomes compromised.

An important element of what the Disaster Management Act requires from departments is that DRR must also consider climate change adaptation, including ecosystem and community-based adaptation approaches. In the country’s currently depressed economic situation, this has a special relevance.

Community vulnerability

“Our high rates of unemployment – further exacerbated by Covid-19 restrictions – mean that communities are increasingly vulnerable,” he said. “This makes disasters far more devastating, both in their immediate impact and their long-term effects on livelihoods and quality of life.”

Mainstreaming DRR into the development planning process is very important for sustainability, and essentially means looking critically at each programme, activity and project being planned – not only to reduce the existing disaster risks but also to minimise the creation of new risks. This makes it vital to apply the law’s requirement for government departments to develop early warning mechanisms and procedures for risks identified in their functional areas – and to regularly review and update these plans.

“This would allow a positive shift of focus towards removing root causes of communities’ vulnerability to hazards,” said Stols. “Increased resilience – which would include better housing, infrastructure, basic services and access to resources – would reduce the dependency on government intervention and other external assistance.”

Such a mainstreaming process would be in line with the United Nations Office for Disaster Risk Reduction’s Sendai Framework for 2015-2030, the Africa Strategy of Disaster Risk Reduction Programme of Action, and the SADC Regional Resilience Framework 2020-2030.

The Sendai Framework, emphasises four basic priorities for action: understanding risk; strengthening disaster risk governance to manage disaster risk; investing in DRR; and enhanced resilience for disaster preparedness and effective response, to ‘build back better’ during recovery, rehabilitation, and reconstruction. Implementing these four priorities will ensure institutionalisation of DRR in any organization.

“Covid-19 has been a wake-up call, demonstrating the wide-ranging and devastating effects of a disaster that we were not well prepared for,” he said. “By complying more fully with our own law and implementing the existing global and regional guidelines, we could take important steps in the right direction.”

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SRK Consulting

More than 45 years of experience underpin SRK Consulting’s contribution to sustainable engineering across a range of sectors – equipping the company to develop and apply integrated, long-term solutions that respect future generations.

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SRK webinar to manage water sustainably, equitably

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Top SRK experts gather to integrate climate change services

As climate change climbs the rankings of business risk, SRK Consulting recently gathered over 50 of its specialists in a virtual workshop to integrate and strengthen its climate change services.

Organised by SRK’s South African Climate Change Reference Group led by Ashleigh Maritz, Philippa Burmeister and Lisl Pullinger, the two-day event included nine parallel sessions discussing over 20 topics.

“Climate change mitigation and adaptation are placing growing demands on businesses in every sector, and on governments.”

SRK Principal Sustainability Consultant Lisl Pullinger

“It is raising social, environmental and governance risks, and threatening economic activity with a range of possible disruptions across the globe.”

Senior Environmental Scientist Ashleigh Maritz highlighted that SRK’s engineers and scientists have for many years been developing tools to monitor and benchmark these risks, and to address them in client’s operations. Key to these efforts has been SRK’s strategic commitment to collaboration.

“Integration between the various disciplines and skill sets of our professionals is really vital in addressing climate change,” she said, “as destabilised weather patterns have countless impacts on every aspect of social and economic life.”

The company’s focus in continuously developing its range of services is to ‘mainstream’ the consideration of climate change in project planning and execution. Critical fields such as water management, environmental impact, infrastructure capacity, social vulnerability and mine tailings design are demanding more attention than ever.

“Our recent workshop explored many of these vital areas, including greenhouse gas accounting, water stewardship, community adaptation, green mine design, tailings management, climate change impact assessment and disaster prevention and management,” said Principal Scientist in Air Quality and Climate Change Philippa Burmeister.

The company’s extensive service offering helps clients to build resilient infrastructure, by posing a range of climatic conditions or design criteria to assess vulnerability and improve resilience. Clients are also assisted with emergency response plans, and with contingency solutions to minimise the consequences of an event.

“A field of particular interest within SRK is the use of data management tools, which capture data efficiently and automate processes such as greenhouse gas (GHG) calculation,” said Burmeister. “The company also uses advanced computing and data science to predict potential climate-change risks and inform design. We combine this approach with a wide suite of professional services, helping clients generate and apply an effective mitigation and adaptation strategy.”

The success of the South African event has led to SRK planning a global workshop in 2021 that will virtually engage specialists from SRK’s offices on all six continents.

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Gas-to-power options emerge on South African energy scene

As South Africa races against the clock to fill an electricity supply gap of some 2 000MW between 2019 and 2022, gas-to-power projects will play a significant role.

Government’s recently launched risk mitigation independent power producer procurement programme (RMIPPPP) has stirred the interest of a number of private players in the gas-to-power sector, according to Nicola Rump, principal environmental scientist at SRK Consulting.

“While the longer-established renewable energy independent power producer procurement programme (REIPPPP) is delivering considerable results in solar and wind energy generation, we are now seeing an exciting start in exploring the potential of gas in South Africa’s energy mix,” says Rump.

She notes that the field of gas-fired generation in the country has previously seen little activity from private developers. This was now changing fast, as the Department of Mineral Resources and Energy prepares to begin evaluating RMIPPPP project bids by the end of 2020. With South Africa’s power system being so constrained, government is wanting these projects to start feeding the national grid by mid-2022. SRK is currently conducting a number of environmental impact assessments (EIAs) for gas-to-power projects in the Eastern Cape and KwaZulu-Natal.

Key aspects of the planning process for these projects, she says, include EIAs and related licencing requirements. Within the tight timeframes envisaged, these need to be carefully managed to avoid becoming stumbling blocks.

“The introduction of strict timelines for the EIA process in recent years means that while EIAs are generally completed in less time than before, the process leaves very little time for accommodating any changes to the project design.”

Nicola Rump, principal environmental scientist at SRK Consulting

It also requires that a significant amount of work must be completed before the application is actually lodged with the regulator. “Gas-to-power projects need to submit a final scoping study to the Department of Environment, Forestry and Fisheries (DEFF), and this must be approved before the EIA phase can begin,” Rump says. “Once the final environmental impact report (EIR) has been submitted, DEFF would decide on the conditions applying to the authorisation.”

While an important attraction of gas is its lower carbon footprint than coal, South Africa’s dominant fuel source for energy, it is not without its environmental impacts. These include carbon emissions, for which projects would require an air emission license before proceeding.  

“Climate change impacts are also becoming an increasingly important consideration in these assessments,” said Rump, “especially in the light of South Africa’s commitments to global climate change and greenhouse gas emission agreements – and its emission reduction targets.”

Other impacts include noise and traffic, as well as effects on the marine ecology of those projects requiring marine infrastructure. Currently, gas-to-power projects tend to be close to ports to facilitate the supply chain from sea-borne liquified natural gas (LNG).

She noted that current projects will have to overcome South Africa’s lack of gas pipeline infrastructure, basing their viability on LNG sources being shipped in. Among the advantages of developing a fledgling gas-to-power sector through the RMIPPPP is that this would contribute to the growth of local gas markets – helping pave the way for the installation of costly gas infrastructure. This is turn would hopefully reduce the cost of gas as a fuel and spur the uptake of this cleaner fuel in South Africa’s energy landscape.

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Professional women forge pathways into mining

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How to achieve shorter water-use licence process

Achieving a 90-day turnaround for the water-use licence application (WULA) process will be a welcome step for the struggling economy, according to SRK Consulting principal scientist Jacky Burke.

Changes will be necessary, though, before the regional and national offices can make a 90-day process a reality, Burke noted.

“It remains vital that the licences issued in this 90-day process will in fact still serve the purpose of protecting our water resources; this means the licence cannot be too generic but should be specific to the activity or operation being authorised, and take into account the specific catchment requirements,” she said. “A shorter processing window is certainly the right approach to support getting our Covid-impacted economy back on its feet.”


Jacky Burke principal scientist SRK Consulting

She said it would also provide real socio-economic benefit to water users – particularly emerging water users – and surrounding communities.  

The Department of Water and Sanitation (DWS) recently revised the regulations on WULA procedures, following a State of the Nation declaration by President Cyril Ramaphosa in February. He announced that water-use licences should be processed in 90 days, rather than the 300 days prescribed by previous regulations.

“Changes to facilitate implementing this new timeframe could include increased engagement between the applicant and the DWS before submission,” she said. “This would allow a review of completed supporting information and designs before the actual submission, so that the 90-day timeframe is focused on final review and administrative aspects.”

Improving the administrative process of compiling the licence could also involve reducing the cumbersome on-line WULA form process into a standardised water use information template, said Burke.

“Such a template could be used to directly generate a populated licence document, without the need to manually recapture the on-line information into the licence format,” she said. “Additional human resources – combined with IT improvements – would also facilitate the effective implementation of a 90-day process for all water use sectors.”

She noted that an ongoing consultative and supportive process between the DWS, applicants, and consultants would also help to fast-track the achievement of a streamlined 90-day application process.  

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Covid-19 calls for ‘balanced’ strategy for technical audits

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