Grid modernization for renewable energy

However, many renewable technologies, with the exception of biogas generated from biomass and anaerobic digestion and geothermal, are intermittent, being dependent on weather patterns. For this reason, renewable energy technologies will have to be incorporated into an overall multi-technology renewable energy package with support from energy storage systems, demand reduction strategies and energy efficiency systems such as smart grids.

Utilities especially are beginning to modernize the grid through the development of smart grids which use information and communication technologies to make the grid more manageable and efficient. However, the success of such a strategy requires the systems and devices to be interoperable with each other, due to their complexity and the number and scale of the devices involved.

The creation of a smart grid basically entails the ‘computerization’ of the existing electricity grid. This can be achieved by installing two-way digital communication technology which communicate with the various smart energy devices managing the grid, each of which can be fitted with sensors in order to gather information. These sensors include power meters, voltage sensors, fault detectors and so on. There will also be two-way digital communication between the devices themselves and a network operations centre which enables the utility to control each device or even millions of devices from one central management location.

The deployment of the data communications technology creates a market in which companies scramble to develop new applications and software. This generates important benefits such as cyber-security and an improved ability to integrate renewable energy technology into the grid, including low carbon transport such as electric vehicles (EVs).

The US has been heavily engaged in grid modernization following the passing of the Energy Independence and Security Act (EISA) of 2007. This provides legislative support for the US Department of Energy (DOE) smart grid programme, creating a Smart Grid Advisory Committee and Federal Smart Grid Task Force as an important part of the process. EISA also established a Smart Grid Regional Demonstration Initiative and directed the National Institute of Standards and Technology (NIST), with DOE and others, to develop a Smart Grid Interoperability Framework. Finance is provided through a DOE Federal Matching Fund for Smart Grid Investment Costs.

The Office of Electricity Delivery and Energy Reliability (OE) is taking a leadership responsibility in the transformation of the US electricity grid with assistance from key stakeholders from industry, academia, and state governments. This involves considerable research and development priorities aimed at responding to the various challenges and accelerating the transformation of the electricity system into a smart grid. This also involves new business models and regulatory policy.

[Image source: Ian Muttoo, Flickr]

Challenges

One of the main problems with the existing grid in the US, and probably other western countries also, is that there has been chronic under-investment, particularly in transmission and distribution. There are hundreds of thousands of high-voltage transmission lines across the US, but only 668 additional miles of transmission have been installed since 2000. This means that system constraints will continue to worsen if the problems aren’t addressed. At present, outages and power quality issues cost American businesses more than $100 billion per year and there have been at least five massive blackouts over the past 40 years. However, if the grid was made even 5 percent more efficient, this would represent an energy saving equivalent to the fuel and greenhouse gas emissions of 53 million cars.

Exacerbating the problem is the fact that we live in a fast-moving digitized society. The need for a transition to a modern renewable economy in order to fight climate change adds extra demands. Currently, the US produces 25 percent of the world’s greenhouse gases, despite having only 4 percent of the global population. Half of the nation’s energy is still generated by coal plants. Meanwhile, nations such as Germany are leading the world in the development of renewable energy technologies such as solar and wind while Japan is moving quickly into the development of advanced energy storage technology and the European Union (EU) has adopted a ‘smart grid agenda’ in which buildings will act as mini power plants.

According to a report by the German Federal Network Agency in January 2015, European national grids face three major challenges in particular, to do with uneven power generation, large scale connection and increased electricity trading.

Uneven power generation is caused by the intermittent nature of renewable energy technology which can cause fluctuations affecting the stability of the grid. This affects both the major long-distance transmission lines and more regional distribution grids.

As energy generation becomes more decentralized (distributed generation), largely through renewable energy systems such as rooftop solar PV and wind farms, a large number of power generation installations are connecting with the grid.

Electricity trading is a particular problem for Germany because of its central location, thereby giving it the status of a transit country between western and eastern European electricity markets. This means it will increasingly have to deal with more cross-border electricity transactions that other countries in the EU.

Requirements of a smart grid

As the US Department of Energy (DOE) explains in its 2010 book The Smart Grid: An Introduction, the new national grids will be intelligent, efficient, accommodating, motivating, opportunistic, quality-focused, resilient and green. What does all this mean exactly?

By intelligent, the DOE means that the system will be capable of sensing overloads and re-routing power in order to prevent outages. It will also be able to operate autonomously at a pace faster than that able to be provided by human manual labor and cooperatively – liaising between utilities, consumers and regulators.

It will be efficient in the sense that it will be able to meet increased demand without the need to install additional infrastructure.

The smart grid will be able to accommodate energy from any fuel source, particularly with regard to renewable energy technologies such as solar and wind. It will be able to do so quickly and efficiently and it will be able to integrate new generation technologies into the system as they are developed supported by new energy storage technologies.

The system will help to motivate consumers towards more efficient management of their electricity supply by providing better communication between householders and the utilities providing their power. This means they will be able to finely tailor their energy consumption depending on their precise requirements according to price and/or environmental concerns.

The smart grid will create new opportunities and markets, thereby generating jobs and contributing significantly to the national and global economy.

It will be quality-focused in that it will be capable of delivering power without risk of power sags, spikes or other disturbances. It will be fully able to support our digitalized society with all its multitude of devices from computers to gaming consoles to smart appliances and other advanced electronics.

The new power grids will be resilient, able to ward off attacks from natural disasters or cyber-criminals through the use of smart grid security technology.

Finally, the system will be green – countering global climate change and making our lives far more sustainable than they are at present.

The DOE categorizes the components of the new smart grid according to five specific technologies. These are: integrated communications, sensing and measurement, advanced components, advanced controls and improved interfaces.

Visualization technology is already being used by utilities for real-time load monitoring and load-growth planning. However, this technology tends to lack the ability to integrate information from a multitude of different sources or display information to different users. Advanced Metering Infrastructure (AMI) is aimed at integrating consumers into a smart grid by giving them the ability to manage their electricity supply more efficiently. It also allows utilities to detect problems more rapidly and operate their systems more efficiently. Price signals will be relayed to smart appliances and smart home controllers and thermostats. These devices will then process the information based on consumer requirements. This will go on in the background with a minimal requirement for human intervention, which in turn will generate significant cost savings. Phasor Management Units (PMU) sample voltage and current at particular locations, taking measurements every 2-4 seconds and thereby enabling situational awareness of the system and preventing blackouts.

Putting it all into practice

Numerous states in the US have now adopted a Renewable Portfolio Standard (RPS) which set targets for renewable energy integration and the recent Paris agreement on action to tackle climate change will mean that even more countries in the world will begin to ramp up their renewable energy infrastructure in harmony with a new global renewable energy market.

However, in the UK, recent cuts in subsidies for renewable energy technologies has placed a question mark over the Conservative government’s ability and/or willingness to invest in or transition to a new smart grid capable of fully integrating renewable energy technology. In May 2015 the trade body for the UK solar power sector, the Solar Trade Association (STA) had to call on the government to do more to invest in grid modernization in order to integrate renewable energy. At present, the UK suffers from ageing infrastructure that will limit the country’s ability to meet its various climate change and renewable energy targets. Six years ago, Western Power Distribution, the District Network Operator (DNO) for the Midlands, south-west England and Wales, had to close the grid to new renewable energy projects, particularly those being developed in Cornwall, Devon, Somerset and Dorset. Meanwhile, parts of eastern and south-east England have hardly any spare capacity according to UK Power Networks.

The UK is obliged, as a member of the EU, to produce at least 15 percent of its energy from renewable energy sources by 2020, but there is increasing concern about its ability to do so. The Office for National Statistics (ONS) said in February 2015 that the UK will have to more than double its renewable electricity to 30 percent if it is to achieve its overall 2020 targets.

“The grid is now sclerotic in places and there are even modest solar roofs that cannot get grid connections” said Leonie Green, the former head of external affairs at the STA. “We are trying to get the DNOs to operate on a more active business model but the amount of solar that is projected for 2023 is less than we have today. We are missing basic information because we don’t have an assessment of how much actual capacity is left and what is needed to meet the 2020 targets. The new secretary of state has no time to waste to get the grid on track if we want a low-carbon electricity system.”

According to Energy UK, it will cost about £30 billion to modernize the UK grid and bring it up to smart grid standards.

[Image source: Wikimedia Commons]

Conclusion

Renewable energy critics will tell you that the intermittency of renewable energy technologies is gradually leading us all into a series of massive, looming power disasters in the near future, but this is little more than propaganda. If the grid is modernized effectively, which it needs to be, then such problems can be effectively addressed. In short, in order to accommodate a renewable energy future, the entire energy grid must be completely transformed. The good news is that this is exactly what is happening now.

“The changes that are coming along, like electric vehicles, like renewable energy, really can’t be accommodated by the existing grids” said independent energy consultant John Scott, speaking to The Guardian in June 2015. Mr Scott is also a member of the SmartGridGB forum, which discusses and promotes smart grid development in the UK. “So rather than making the grid bigger and bigger… smart technologies allow you to get much more out of what you already have.”

According to Dr Luis Nando Ochoa, a senior lecturer in smart distribution networks at the University of Manchester, either the UK will have to pay millions of pounds to reinforce its current grid or it will have to adopt smart technology. With the latter option, things can be controlled more effectively with the same infrastructure, which behaves much more intelligently.

Things are indeed changing fast, but there again they need to. We’ve waited too long and change is long overdue.