Capacitive Transfer System: transforming the electricity sector

capacitive transfer system

Enertechnos explains the changes in the way electricity is generated and consumed and outlines how its Capacitive Transfer System is capable of reducing electric power system losses.

Enertechnos was created to develop, patent and commercialise Capacitive Transfer System (CTS), a newly invented form of electrical transmission cable, which could be capable of reducing electric power system losses from a global average of 10.6 per cent; 8.7 per cent in North America and 7.2 per cent in Western Europe.  The cable is patented in the UK, USA, Japan, Mexico, Eurasia and South Africa and patents are pending in significant markets in the rest of the world.

The global power cable and wire segment of the power transmission and distribution (T&D) market is forecast to be worth approximately $90 billion (~€79 billion) by 2020 The Capacitive Transfer System could benefit this market in terms of reduced capital and operating costs by delivering power over distance at higher efficiencies than conventional technology.

Key highlights

The electricity sector is going through a major transformation: the ways in which electricity is generated and consumed have changed dramatically over the last decade and this transition is expected to continue. The transmission and distribution of electricity is a fundamental part of the electricity value chain. Capacitive Transfer System is a breakthrough and potentially disruptive technology: the Enertechnos Board believes it is the first fundamental change to power cable geometry and fabrication in decades, whilst still leveraging existing cable-manufacturing technology. Its material benefits over existing conventional cable technology include:

  • Lower delivery losses resulting in lower generating costs and carbon emissions: up to 40 per cent more power would be deliverable via Capacitive Transfer System than with conventional cable from the same power source (subject to power input and load factors);
  • Lower capital costs: reduced need for alternating current (AC) booster transformers or high voltage direct current (HVDC) converter stations which can comprise up to 40 per cent of project capex, since CTS has materially less voltage drop than existing wire and cable;
  • Lower ongoing operating costs:  reduced operating and maintenance requirements owing to significantly fewer transformers and converter stations, as explained above;
  • Expected lower earth leakage:  greater lengths of Capacitive Transfer System cable can be buried underground than conventional cable, reducing the need for overhead pylons;
  • Expected lower electro-magnetic emissions: cable can be routed alongside existing infrastructure within a reduced ‘quarantine area’, and more easily co-packaging with communication links;
  • Successful outcomes of testing programmes corroborated by National Physical Laboratory (NPL), demonstrating validity of CTS operating principles;
  • Agreement with Western Power Distribution (WPD), the largest Distribution Network Operator (also known as Distribution System Operator) (DNO/DSO) in the UK, to install (subject to testing) circa 15km of Capacitive Transfer System running at 33kV three-phase. Three-phase electric power is a common method of AC electric power generation, transmission, and distribution. It is a type of polyphase system and is the most common method used by electrical grids worldwide to transfer power;
  • Manufacturing agreement with Grupo Cabelte, a leading European cable manufacturer to produce production standard 33 kV cable for testing. The cable has passed acceptance testing at the factory and has been delivered to Enertechnos;
  • Letter of intent (LOI) from Tratos – Tratos Cavi is the second-largest Italian manufacturer of cable for the T&D market;
  • Licence signed with Tratos – following the LOI, Tratos signed a Licence Agreement on 24th September 2018;
  • Final designs of cable for type-certification completed;
  • Intellectual property secured: multiple patents assigned and an ongoing process of ring-fencing patent applications; and
  • Vast market opportunity: Capacitive Transfer System is a unique, patented concept capable of disrupting a large ($90 billion by 2020) existing global market.

Moreover, if the current exponential growth of key areas such as the electrification of vehicles continues, the addressable market opportunity could increase dramatically. Enertechnos’ proposed licensing-led model will be capital-light, with the result that projected cash flows/returns will be significantly enhanced by even very marginal increases in its share of target markets.

There are approximately 67.1 million kilometres of T&D cable and line installed globally. The typical life of a cable is 40 years and so there is a rolling replacement programme in place, giving grid owners and/or operators the opportunity to upgrade to the latest cable technology. Using the lower-loss Capacitive Transfer System cable could mean more delivered power, which in turn means less power would need to be generated and so a considerable amount of CO2 emissions could be prevented.

UK system losses were 26.554 terawatt hours (TWh) in the 12 months to 31 March 2017 – enough to power nearly seven million homes for one year.  Calculated at the average wholesale spot price for electricity in the same period, the total cost of UK losses would be approximately £1.1 billion per year. UK energy regulator Ofgem has highlighted that electrical energy losses account for 1.5% of the UK’s greenhouse gas emissions and that they are the largest part of a DNO/DSO’s carbon footprint. Loss savings from implementing the Capacitive Transfer System could contribute significantly to targets set by international policies on greenhouse gas emission reduction.

Market entry applications include: (i) national T&D grids; (ii) private wire networks or rural micro-grids, the latter particularly in developing countries; (iii) links to isolated loads such as island or mining communities, or outback farms; and (iv) subsea power-from-shore (PFS) links to offshore oil & gas platforms and offshore-to-offshore links.

In addition, Capacitive Transfer System should also be suitable for potential game-changing applications such as:

  • Repowering onshore and (over time) offshore wind farms;
  • Smart grid;
  • Co-packaging with data/communications cables; and
  • Grid reinforcement for electrification of vehicles: UK and French (to name but two) government mandates on prohibition of petrol- and diesel-only vehicles by 2040 will place significant additional imperatives on grid reinforcement.

A marketing programme of the Capacitive Transfer System to DNO/DSOs, regulators, government and other potential users has already commenced. Enertechnos’s experienced team – Dominic Quennell (Founder and MD), Gareth O’Brien (Operations Director), Charles Lucas-Clements (Business Development Director) Dr Mansour Salehi-Moghadam (Senior Research Engineer) and Dr Yang Yang (Research Engineer) – are actively supported by a seasoned Advisory Board. As lead partner in a group of four collaborating partners, the company has been awarded a UK Government grant of £1 million for research and development. This is a noteworthy validation of the progress made by the company in recent years. The company, with its partners Brunel University London and TWI, passed three successive quarterly reviews of the project by the government-appointed Monitoring Officer in January, April and July 2018.

Value proposition

Capacitive Transfer System is expected to have lower power losses than conventional cable. This means:

  • CTS provides cable manufacturers with an enhanced product to offer grid owners and operators, thereby encouraging increased sales revenues;
  • Grid owners and operators benefit from lower infrastructure costs and potentially a faster permitting process if undergrounding;
  • The “societal cost of losses” is set in the UK by Ofgem at £48.4210 per megawatt hour (MWh) – this is an arbitrary cost based on 2013 wholesale pricing – so operating costs of the grid are considerably reduced if losses are reduced. Similar cost structures are to be found in other countries;
  • Losses must be declared by UK DNO/DSOs as part of their corporate carbon footprint;
  • Power generation owners benefit by being better able to match their production to demand requirements rather than having to over-produce to compensate for transmission losses;
  • Capacitive Transfer System saves CO2 emissions because less extra capacity is required to cover transmission losses (note: these CO2 emissions savings are significant and contribute to inter-governmental agreed targets for greenhouse gas emission reduction targets). 1.5 per cent of UK CO2 emissions are attributable to system losses in T&D;
  • Enables more use of renewable energy via long subsea interconnectors and cuts cost because power can be transmitted by AC rather than HVDC with additional costs for inverters, rectifiers and filters; and
  • Lower losses might lead to lower balance of payments deficit for imported hydro-carbon generated power.

Capacitive Transfer System is expected to emanate less heat and lower levels of electro-magnetic emissions so that:

  • Cable can be routed alongside existing infrastructure such as rail, road and water distribution networks;
  • There will be no further need for a substantial “quarantine area” (which can be 60-100 metres wide) beneath pylons, meaning less real estate is required;
  • Capacitive Transfer System cable is more easily buried – resulting in a win-back of real estate from pylons, aesthetically is far more acceptable and the permitting/consenting process for installations is considerably shortened;
  • Pylons can be dismantled and recycled; and
  • Capacitive Transfer System could enhance smart grids by enabling embedded communications cable for downstream load management.

CTS is expected to behave similarly to DC cable in terms of impedance, but without the inverters, filters and rectifiers required by a DC transmission line, which cost up to 40 per cent of a typical DC transmission line installation. This is crucially important for subsea interconnectors and for offshore wind and tidal stream applications.

Capacitive Transfer System will be able to balance capacitance and inductance in a transmission or distribution line: this has significant advantages, in particular where a large-scale industrial consumer has a factory using, for example, many motors, for lathes. In this mode, the beneficial properties of Capacitive Transfer System extend beyond the cable itself to the system as a whole. Empirical testing by Enertechnos has shown that connecting a length of Capacitive Transfer System cable to a length of conventional cable improves the performance of the conventional cable in terms of voltage drop and power delivery. This behaviour is also being modelled using COMSOL Multiphysics software.

Market

The cable manufacturing market is diversified and global. Simply put, it splits into three key types of business: ‘pure-play’ cable manufacturers with global reach; large industrial or conglomerate businesses which have a cable division(s); and smaller cable companies with a more local focus. In due course, the Company may opt to retain certain specialised low-volume, high-margin niche markets for itself by having Capacitive Transfer System cable manufactured on a sub-contractor basis in order to supply those markets.

Marketing approach

Enertechnos believes that the applications for the cable could be numerous and far-reaching.  As such the business case for a cable manufacturer to invest in a licence should be strong. It could provide the early adopters with a key competitive advantage.  We believe that the inherent cost savings and benefits associated with Capacitive Transfer System are sufficiently material that cable manufacturers and/or cable users will find it increasingly difficult to compete for major projects without access to CTS technology.

Key stakeholders include governments, who will be interested in:

  • Impact on CO2 emissions;
  • Security of supply;
  • Cost to business and households (inflation and cost of living reference);
  • Smart energy and reduced system losses; and
  • UK government will be interested in export revenue generation.

Grid owners and operators will be interested in:

  • Reduction of infrastructure costs;
  • Faster permitting process for Capacitive Transfer System cable;
  • Reduction of energy and power losses;
  • Increased reliability of grid;
  • Increased “reach” of grid (e.g. international transmission of power); and
  • Enhanced management by embedding data cables in CTS.

Power generators are projected be interested in:

  • Reduced generation requirement;
  • Reduced infrastructure costs;
  • Increased efficiency; and
  • Potential avoidance of costly AC/DC conversion devices.

Consumers at every level, who are primarily concerned with reducing costs and maintaining security and reliability of supply, are aware of the increasing challenges and limitations in electricity supply. The message will be that Capacitive Transfer System is expected to go a long way to reducing such issues to a more manageable level.

Potential growth areas for Capacitive Transfer System

In additional to general T&D grid installation/replacement opportunities, there are several growth areas where CTS could be particularly applicable. Among these are:

Wind farm repowering

Wind farm repowering programmes are underway in more mature wind markets such as Germany to repower older wind farms with new turbines.  Repowering is a cost-effective way of re-using existing brownfield sites (which are typically the best sites, having been the first to be developed) through the use of larger and more efficient turbines.  Site output can be increased materially as a consequence of increased capacity and/or improved capacity factors arising from the use of more efficient and higher hub height turbines.

A 2MW wind turbine coming off the production line now with a rotor diameter of 80 metres can generate four to six times as much electricity as the around 1GWh annual yield of a typical 500kW wind turbine with a 40 metre rotor built in 1995. For example, in Germany in Schneebergerhof in the Rhineland-Palatinate region, Juwi has replaced five Enercon E66 1.5-MW turbines with five 7.5-MW E126 machines, amongst the largest operational wind turbines in the world today. These generate more than six times the power of the old turbines — around 20GWh annually instead of the original 3GWh. Because the original sites already have permits in place, allied to the fact that the local community is usually supportive and well-accustomed to having a wind farm in its vicinity, the permitting process in many countries for repowering is considerably easier and shorter than for new greenfield sites.

Most of the global cumulative wind power nameplate capacity has been recently installed, but a sizeable percentage — nearly 17 per cent, or 73,957 MW — was at least 10 years old in 2015. One consequence of this technology’s aging is reduced performance. According to some experts, wind turbine load (or capacity) factors decline markedly with age. A 2014 study from the UK’s Engineering and Physical Sciences Research Council of load factors recorded for 282 onshore wind farms in the UK between 2002 and 2012 found that wind turbines lose around 1.6 per cent of their output per year, with average load factors declining from 28.5 per cent when new to 21 per cent after nineteen years. The Council noted that the trend is consistent for different generations of turbine design and individual wind farms.

Typically, the cables installed to transfer clean power from the wind farm to the grid were specified at double the maximum power output of the original turbines installed; clearly, with an increase of up to six times output through re-powering, many existing cables will have to be replaced. This represents a major opportunity for Capacitive Transfer System with its characteristics of low loss, potential to transmit power at lower voltages and its ability to be buried over greater distance than conventional AC cable.

Electric vehicle adoption

Sales of electric vehicles (EVs) continue to exceed forecasts by a considerable margin. The range of expectations includes a forecast that EV sales will grow from 462,000 globally in 2016 to 41 million in 2040. This fleet would consume an estimated 2,700TWh of electricity, equivalent to 11 per cent of global electricity demand in 2016. This increase in power consumption will have a massive impact on distribution grids. It has been estimated that plugging just six EVs into the grid in a single street in the UK could cause brown-outs.

Several national governments have recently announced that by 2040 no new petrol- or diesel-only cars or vans will be permitted to be sold. According to a National Grid report, peak demand for electricity to power these vehicles could add around 18GW to the current peak of 61GW. Delivering this power to consumers will place huge demands on the grid and so grid reinforcement requirements leveraging the benefits of Capacitive Transfer System technology may offer significant opportunities.

Executives of the Company have met officials from the Office of Low Emission Vehicles (OLEV) section of the UK Department for Transport (DfT) to review the challenges confronting governments wishing to expand the electricity grid network to supply power to EVs.

The Ofgem “My Electric Avenue” research project concluded that powering EVs would mean that across Britain 32 per cent of low voltage circuits (312,000) will require reinforcing when 40 to 70 per cent of customers have EVs based on 3.5kW chargers. These problems will only be exacerbated when 7kW chargers are used. Plans in place for a series of 350kW fast-chargers in Europe by IONITY, a consortium of Daimler-Benz, BMW, Volkswagen and Ford, will place an even great strain on the distribution network.

The Enertechnos Board believes that Capacitive Transfer System, as a new concept in low-loss cable based on capacitor technology that is expected to enable electric power to be transmitted with extremely low reactance, and with a power factor near unity (i.e. high proportion of useful active power required by most electrical applications), could address many of the issues confronting grid owners and operators should the successful development work to date continue on a similar trajectory.

Data from tests of three different configurations of Capacitive Transfer System indicate it should deliver electric power with lower losses and reduced reactive impedance over much greater distances than conventional cables, eliminating the need for many voltage booster transformers. Tests have strongly indicated that CTS can be undergrounded over longer distances than conventional AC cable with lower losses caused by capacitive coupling to earth. CTS may also be suitable in its unsheathed form for overhead transmission line installation. It may have lower electro-magnetic emissions than conventional cable as well as lower losses; future testing is planned to determine this.

Capacitive Transfer System cable offers significant advantages over conventional cable yet can be built on the same equipment without modification. It is fully compatible with existing grids and is designed to the same standards as conventional ohmic cable.

Dominic Quennell

Managing Director

Enertechnos Limited

+20 3865 6381

dominic.quennell@enertechnos.com

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http://www.enertechnos.com/

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