Renewable energy—wind, solar, thermal, hydro, and biofuel—contributes less than 10% of the world’s energy supply. The Internet of Things (IoT) could help raise those numbers.
Renewable energy power plants tend to be geographically dispersed, but with the IoT, remote asset management becomes possible. So too does adapting to volatile and harsh environments, reducing equipment breakdown and loss. IoT sensors continuously collect data that helps managers identify and execute the most viable production and distribution strategies. Using IoT data analytics, predictive maintenance can prevent costly downtimes.
Thanks to the IoT, renewable energy power plants are reducing their operating costs by optimizing production and control and minimizing the cost of repairs.
In this article, we’ll discuss the obstacles faced by the various renewable energy subsectors and how the IoT can help move them forward.
Solar and Wind
So far, the IoT’s renewable energy role is most prevalent in the solar and wind sectors. Solar and wind are also two of the larger subsectors within the renewable sector and certainly the fastest-growing.
Wind turbines and solar panels are expensive and complex constructions that are often installed in remote and harsh environments. The IoT has a vital part to play as plants rely on it to help managers operate, adjust, monitor, and maintain the equipment—all while reducing costs and optimizing energy production and distribution.
Government Subsidies
Right now, renewable energy is more heavily subsidized than conventional energy sources ($6.68 billion to $489 million, respectively, in 2016). Most of the subsidy comes in the form of tax breaks, where wind and solar claim the largest share. The wind and solar tax credits are set to expire at the end of 2021, though a 10% investment tax credit for solar will remain.
Future government support for wind and solar is uncertain. Subsidizing of other subsectors—such as tidal, wave, hydro, and biowaste—is minimal and will likely remain so. With the possibility of lower subsidies looming, the renewable energy sector may need to increase innovation to stay competitive. Applying the strengths of the IoT may help it do just that.
Tidal Energy
Tidal energy is one of the earliest renewable energy sources—tide mills existed in medieval times. Mounted along coastlines, tidal power plants can generate electricity when low tides and high tides differ in area by five meters or more.
Its energy-harvesting equipment is underwater, so a benefit of tidal energy is low noise and visual impact. Also, tidal energy plants can potentially reduce the risk of floods. A study published by the Royal Society (UK) has demonstrated that tidal power can meet 20% of the UK’s power demands.
Technologies
Many tidal energy systems have been developed to optimize energy harvesting. For example, tidal barrages can be installed across an inlet, bay, or lagoon to form a tidal basin. Gates on the barrage control water levels and flow rates to create a two-way system that can generate electricity from incoming and outgoing tides.
Although tidal turbines resemble wind turbines, tidal turbines need to be much sturdier and heavier because water is around 800 times denser than air at sea level. Tidal turbines also generate much more energy than wind turbines.
Similar to tidal turbines, tidal fences have vertical axis turbines mounted in a fence or placed on the seabed in rows. Tidal fences generate electricity with the water passing through the turbines.
Adoption
There are ongoing tidal barrage projects in the EU as well as Asia. A tidal turbine project is even being developed in New York. Meanwhile, tidal fences are still in the development phase.
Overall, by the end of 2016, all the generated tidal energy in the world amounted to approximately 0.5 gigawatts of power. However, there are no more installation plans in the foreseeable future.
The Role of IoT
Several factors are contributing to tidal energy’s lack of development. Tidal energy requires significant upfront investment. Also, the harvested energy needs to be distributed to inland consumers. In addition, rough weather changes the consistency of the waves and reduces energy production.
A fuller, more systematic understanding of waves and streams will help tidal technologies to become more reliable and productive. The IoT can contribute to this goal significantly through continuous data collection and the use of analytics.
Better Design
IoT sensors located near or in the seabed will help collect the large datasets necessary for accurately modeling ocean currents. Such modeling will help engineers design better and more appropriately fortified undersea systems with lower machine attrition and more efficient energy harvesting. As efficiency increases, the cost of tidal energy—currently 10 times more expensive than traditional nonrenewable sources—will decrease.
Better Energy Resource Mapping
Another critical step in making ocean-generated energy more feasible is the characterization and mapping of ocean energy resources.
For example, engineers need to identify the areas with the highest wave energy, as quantified by parameters like total annual wave energy, significant wave height, wave energy period, and mean wave direction. The estimation and description of available wave energy at high spatial and temporal resolution are needed to properly plan and design ocean energy converters. These converters can maximize energy production and reduce inefficiency.
Better Environmental Assessment
Right now, the environmental impact of tidal energy plants remains a controversial subject, with data supporting both sides of the debate.
On one hand, evidence suggests that wave energy plants may threaten ocean floor habitats, killing marine life that swims too close to the turbines. In addition, the tidal arrays may change the dynamics of the sediment and cause unforeseen consequences. On the other hand, it’s argued that the current data is not definitive and that the impact of wave energy will be minimal to marine animals while providing significant socio-economic benefits to humans.
Therefore, it is vital to have in-depth environmental assessments. With the use of IoT sensors and analytics tools, it’s possible to collect more data and evaluate the impact of the relevant technologies, in turn reducing uncertainty and enabling investors to make immediate and correct decisions.
Using the IoT to Understand the Costs
Lastly, the IoT can also help engineers understand the real cost of scaling ocean energy.
Currently, little actual data exists on scaling costs. Up until now, computer modeling has mostly been relied on for cost estimates. However, using the IoT can offer a more direct understanding of operating, installation, and grid connection costs. IoT analytic tools can also help model the potential savings of predictive maintenance.
Wave Energy
The WaveRoller converts wave energy to electricity. (Image courtesy of AW-Energy.)
Technologies
As a relatively new renewable energy source, wave energy technologies are still evolving.
For example, the Oscillating Water Column by Ocean Energy powers its turbine with the vacuum created by wave motion that forces air up and then pulls air down. Hyper Drive Corporation of Japan is developing a wave power generator on a buoy that absorbs energy by expanding and contracting with the waves. Finavera Renewables has developed a floating structure that converts the up-and-down motion of waves into electricity. Australian company Carnegie Wave has developed a device that uses wave power to pump water to shore to generate electricity. Lockheed Martin’s Australia project is developing a buoy technology that harnesses wave energy as well. M3 Wave has developed a pressure-based device that generates electricity from being spun by passing waves.
Underwater data center development by Microsoft and others is propelling the interest in wave energy. Considered by some to be doubly environmentally friendly, underwater data centers use electricity converted from wave energy and the seawater for cooling the computers.
Adoption
As a relatively new form of renewable energy, wave energy is not widely deployed commercially.
According to the U.S. Federal Energy Regulatory Commission, although it has issued more than 30 preliminary permits for exploring tidal or wave projects, no ocean wave energy facilities in domestic waters were connected to the power grid as of 2020. The U.S. Department of Energy has funded wave energy research by universities such as Oregon State University and the University of Washington.
The Role of IoT
In pilot projects, wave energy converters have been installed along, near, or away from the shoreline to maximize energy output.
Because the energy converters would typically be installed in remote and challenging locations, many concerns must be addressed to reduce the risks to investors.
First, saltwater is a hostile environment for any device. Second, the waves are challenging for energy harvesting as they not only roll past a device but also bob up and down or converge from all directions; they can be a nightmare to designers.
The IoT helps designers collect and analyze data to address these concerns. For example, performing survivability and fatigue analysis can ascertain how the environment will affect converter lifespan and determine the ideal mooring solution for the converters. Also, IoT sensor data and modeling can shed light on how different wave conditions affect energy production.
In addition, using sensors connected to the IoT allows engineers to assess the environmental impact of the converters, such as if and how the converters affect the seabed sediment or the hydrodynamics. Those tasked with determining, planning, and managing the cable routing that distributes the harvested energy to the grid also rely on the IoT.
An IoT-related invention called WaveRoller, which is an oscillating surge converter, has recently gone into the testing phase. One IoT system automates the management of WaveRoller in varying conditions. The system uses artificial intelligence to decide the level of hydraulics to use against each wave so that it can capture the maximal amount of energy each time. At the same time, the system also prevents the converters from overloading. Another IoT system manages the storage and distribution of the electricity generated by the converters.
Hydropower
According to REN21’s 2017 Global Status Report, among all renewable energy sources, the greatest amount of power has been generated from hydro and the lowest amount from tidal. Today, about 16% of the world’s energy demand is met by hydroelectricity, and 71% of all renewable energy is supplied by hydropower.
Adoption
Unlike other renewable energy sources, hydropower is a much more mature technology. The adoption of hydropower is also much higher.
The environmental impact of hydropower is well understood. Hydropower plants are often inefficient. For example, most U.S. hydroelectricity facilities use more energy than they produce. The storage systems may need to use fossil fuel to pump water. Therefore, it is unlikely that there will be an investment in new hydropower projects.
Overall, the hydro sectors have been slow to adopt the most updated technology for operation or maintenance.
The Role of IoT
Despite the drawbacks, the IoT can help make hydroelectric facilities more efficient, adaptable, flexible, and competitive against other energy sources.
More so than other power plants, hydro plants have the problem of aging equipment, which often causes costly and unexpected breakdowns. By scheduling predictive maintenance with the help of the IoT, plant owners can help reduce the cost of such breakdowns. In addition, the IoT can help automate plant operations, decreasing labor costs.
With localized sensors, IoT can reduce data storage requirements. Currently, the amount of data transmitted for quantitative analysis—temperature, pressure, water level, power output, turbine rotation, vibration, etc.—is estimated to be 3.5 terabytes of data per year at a typical hydro plant. The fact that the data are usually stored in isolated systems makes it challenging to integrate the data and analytics for decision making. IoT sensors enable 24x7x365 data collection that will allow for more granular, accurate, and real-time analysis.
Biomass Energy
Biomass fuels provided about 5% of total primary energy use in the United States in 2017. Of that 5%, about 47% was from biofuels (mainly ethanol), 44% was from wood and wood-derived biomass, and 10% was from the biomass in municipal waste.
Technology
Among the different methods in generating energy, the direct burning of food or waste for fuel is not as eco-friendly as using waste to generate biogas. Biogas consists of methane and carbon dioxide; methane is the main ingredient of natural gas.
The cleanest biogas can be generated from food, yard, and wood waste or animal manure and human sewage in landfills.
Need
The generation of biogas is fairly straightforward compared to other renewable energy creation methods. However, because methane is flammable, safety will be a major concern.
Research has shown that IoT sensors can be used to monitor biogas production. Installing IoT sensors to monitor various parameters such as pressure and temperature can help detect and prevent leaks and explosions.
Power-to-Gas
Storing excess energy is possible using a power-to-gas process. Renewable electric power can be converted into storable biogas (methane) or hydrogen. The biogas or hydrogen can be converted to energy later or injected into a natural gas pipeline for transport.
IoT-based monitoring of the power-to-gas process has been proposed. Since the production of methane is also involved, IoT sensors used to detect gas leaks will help ensure the safety of the facility. Overall, incorporating equipment and systems in the IoT has the potential to reduce operational and support costs.
There are many power-to-gas demonstration projects in Europe. In the U.S., SoCalGas has ongoing demonstration projects in collaboration with the University of California at Irvine and the National Renewable Energy Laboratory.
Comparison and Analysis
Future Outlook
The government-provided subsidy amount affects the speed of development of a subsector and also correlates with IoT use. Wind and solar have made much progress in recent years, partly due to significant government support in the form of tax breaks. They also happen to have the broadest IoT adoption.
On the other hand, other subsectors have not seen much IoT application for various reasons. Hydro is the most established sector and has the most mature technology; therefore, it does not need the IoT to develop further. Tidal and wave energy are far behind in technology development due to a lack of governmental support and the higher complexity of their working environments. Biomass energy operates in a less demanding environment, but it is viewed as a less appealing option; as a result, its popularity is minimal. Lastly, power-to-gas is fairly new and, therefore, early in its development. As a result, all of these sectors are much slower in incorporating the IoT into their operation or development.
The stage of technology development determines the type of IoT application.
For the subsectors that are in early R&D, the IoT can play a role in gathering research data and validating the feasibility of scaling up. For tidal and wave energy, which work in the most complex and demanding environments, engineers will need numerous integrated datasets to model the turbine design. In addition, the IoT will be essential in assessing the environmental impact of these technologies accurately and thoroughly. Also, the IoT can help identify the optimal location for building the facilities.
For the subsectors that involve mainly chemical processes, like biomass and power-to-gas, the IoT will be useful in optimizing production and ensuring workplace safety.
For hydropower, which has the most established and mature technology, the application of the IoT will focus on management and maintenance areas.
Overall, the different renewable energy subsectors have different needs that can be addressed with diverse IoT applications. Regardless of the application, the IoT can help different subsectors achieve the common goals of risk and cost reduction.