Behind the Meter↓

Behind the Meter (BtM) power generation describes all power generated on the property and fed into the property directly before the meter and before export. Also known as “Self-Generation”.

Front of Meter↓

Front of Meter (FoM) is when energy generated on your property goes directly into the grid and you become a “Generator”.

Solar Farm↓

A “Solar Farm” can be defined as 1MW and above. Under that power output the term “Solar Fields” is more appropriate. A “Solar Park” may be a collection of Solar Fields or a Farm or several farms.

Macro Renewables↓

The States of Guernsey policy presently defines Macro Renewables as 50kW and above. States of Guernsey website: https://www.gov.gg

Micro Renewables↓

Micro Renewables are under 50kW.

Guernsey Electricity Limited (GEL) additional “Standby Charges” are presently set from generation outputs of 25kW.

Generation Licence↓

For 500kW and above a generation licence is possibly required, depending on law which may or may not be applicable at the time of implementation.

Power Purchase Agreement↓

Under 500kW and above 25kW a Power Purchase Agreement (PPA) can be sought from GEL as a Generator of electricity which maybe a stand-alone with no home or premises attached. If associated with an establishment in that case there are no Standby Charges for the premises as it is Front of Meter generation. If standalone there are no Standby Charges, the agreement is based on Generating direct to grid, rather than behind the meter (with excess spilling to the grid), and will be covered by a PPA. Under the current merit order dispatch models this would either align to the import or on island generation marginal costs.

Embedded Generation↓

Micro-scale to macro-scale generation of electricity embedded within the electricity network and also known as “Distributed Generation”, i.e. power from small to large is distributed and embedded within the network, not centralised. Centralisation of power generation has been the utility tradition for a very long time (all power utilities). This presents new challenges to network operators and centralised generators, operationally and financially - and we are all treading new paths here. This embedded generation applies not only to our main focus of solar generation of electricity from light but also wind, hydro and tidal. In Guernsey a small amount of localised on-island micro-wind energy and micro-hydro is possible for those close to such a resource. Offshore tidal and wind that is essentially macro in scale may be embedded or external depending on how we treat it and is to be encouraged.

It is important to understand that Embedded Energy Generation applies not only to our main focus of generation of electricity but also any other renewable power generation - and must include heat pumps and solar thermal heat generators, known collectively as Renewable Energy Devices (REDs) and include all types of REDs.

Embedded power generation also includes Combined Heat and Power (CHP) systems which are traditionally gas or oil-fired but could also be Fuel Cells (hydrogen gas generators that produce heat and electricity) or even hydrogen powered micro or macro generators producing electricity only. It also includes all type of storage units that may only use renewables to charge them but also use grid electricity to charge on low rates or simply to maintain the charge, and may or not be battery based, and include supercapacitors, heat storage or compressed air or liquids or other.

There are a multitude of possible embedded energy devices, some producing electricity, some using electricity, all reducing the amount of electricity required to be generated at the wider centralised scale.

Zero Energy Building (ZEB)↓

When a building, a business or a community produces as much energy annually as it uses it can be classed “Zero Energy”. This is better than the definition of ‘carbon zero’ otherwise nuclear supporters try and claim a win.

Energy-Positive↓

When a home, business or economic jurisdiction produces more energy than is uses and able to export the excess and profit from the exercise.

Energy-Negative↓

When a home, business or economic jurisdiction uses more energy than it produces and has to import most of its energy if not all its energy.

With an ever-changing cost environment due to the ever-changing renewable energy streams we need a pricing system that works with the reality. Smart Grids mean when the sun is shining and the wind is high, the tide is running, electricity will be dirt cheap. In that case internet-connected systems will be informed of the tariff at the time and in the case of domestic properties, due to a home automation program reacting to a signal, your hot water will get hotter, your fridge colder and your home’s batteries and EV will be charged. Commercial entities will charge supercapacitors, flow batteries, make hydrogen gas. When there’s no sun, no wind, and the tide is turning the internet will tell us energy is expensive and to utilise our thermal stores, turn off non-critical appliances, and switch on the battery systems and the hydrogen generators. Its likely that there will be small-scale hydrogen generators at small-commercial and domestic level able to enjoy the use of renewables when in excess.

V2H – Vehicle to House.↓

When an electric vehicle owner uses the on-board battery to power their home at night rather than buying specific storage batteries to undertake this function. V2H may become popular for those cars left predominantly at home where the car and home owner travels just 50 miles a week for errands and close visits.

Using your own solar PV array or other renewable energy system to charge an EV it makes the EV more energy efficient and you become self-responsible for your own transport. Any growth in EV without parallel growth of island-generated renewables will result in more energy used not less and unless we generate our own it will be imported energy.

V2G – Vehicle to Grid.↓

In this case the electricity utility encourages vehicle owners to bolster their grid in need. Probably not likely to be a popular option in Guernsey. It would be better to maintain grid stability with more reliable means. There is a psychological phenomena called “range anxiety” which may or may not mean drivers are happy with the utility grabbing their power even though these systems are designed to maintain your range for when you demand it.

V2B - Vehicle to Business↓

This describes the transmission of energy from dormant business-owned and operated vehicles that may be left overnight on business premises to and from bi-directional electric vehicles. The idea is at the end of the day, once charged they can be discharged to help offset power used overnight or reduce grid supply costs. Very much more oriented to UK, European and US grids. We are not sure this will catch on in Guernsey, but with a Smart Grid, there could be times when power rises in cost overnight and discharging the battery at peak expense might be helpful. But at the same time is it not better to have a proper storage contingency for your business that encompasses grid stabilisation, storage for expensive peaks and have a UPS capability?

V2B - Vehicle to Building ↓

Also known as Vehicle to Building, it’s the same technology as the other V2B, V2G and V2H terms allowing vehicles to charge and discharge automatically.

Levelised Cost Of Energy↓

Forget the payback its all about the LCOE - The levelised cost of energy or LCOE is similar to payback for energy systems, but more importantly rather than measuring number of years to get back the investment, the LCOE works out how much money can be made per kWh to recoup lifetime costs. This includes the initial capital investment, maintenance costs, the cost of fuel for the system (zero for PV, wind and tidal for example), any operational costs and the “discount rate”.

The importance of this is that when comparing a gas-fired generator or oil-fired boiler or a nuclear power station and you level out all the costs, which is significant for fossil or nuclear powered stations, renewables looks very low cost to buy and run in comparison.

Smart Grid↓

With an ever-changing cost environment due to the ever-changing renewable energy streams we need a pricing system that works with the reality. Smart Grids mean when the sun is shining and the wind is high, the tide is running, electricity will be dirt cheap. In that case internet-connected systems will be informed of the tariff at the time and in the case of domestic properties, due to a home automation program reacting to a signal, your hot water will get hotter, your fridge colder and your home’s batteries and EV will be charged. Commercial entities will charge supercapacitors, flow batteries, make hydrogen gas. When there’s no sun, no wind, and the tide is turning the internet will tell us energy is expensive and to utilise our thermal stores, turn off non-critical appliances, and switch on the battery systems and the hydrogen generators. Its likely that there will be small-scale hydrogen generators at small-commercial and domestic level able to enjoy the use of renewables when in excess.

Hydrogen↓

Gas that can be extracted from water. Most of us know water as H2O – two hydrogen atoms and one oxygen atom. The main method of extraction of hydrogen from water is called electrolysis. At the same time oxygen is extracted and can be stored for later recombination with hydrogen or vented to atmosphere. Hydrogen can be stored in tanks, transported in tankers or distributed in robust pipelines. It is safer than hydrocarbons due to its light weight, it escapes quickly, but would leak easily from conventional pipelines. It is pronounced safe to use in domestic properties by various UK gas authorities and organisations after much testing. Oxygen can also be stored. When hydrogen is recombined with oxygen it produces energy – very slowly in the case of fuel cells which are the opposite of electrolysis cells and very quickly in the case of electricity generators, or hydrogen gas boilers or hydrogen internal combustion gas engines. In all cases the by-product is water.

Hydrogen can be used to power all types of transport from small cars upwards, depending on the weight of the technology used. It is likely that larger vehicles such as large cars, heavy vans, buses, coaches, taxis, lorries, large boats, ships, aircraft, rocket ships, boilers, generators will use hydrogen. Its more appropriate for hydrogen to power these larger vehicles than smaller ones because of the power to weight ratio, and its more appropriate for smaller vehicles such as standard domestic cars to be powered by lightweight lithium batteries (or other, as new batteries are developed). Therefore we will have a mix of direct electric charging of most ordinary cars on the roads and use stored hydrogen created from renewable power for the more commercial aspect of transport – including larger shipping and aircraft. Again smaller air vehicles are likely to be electric and utilise batteries.

Prosumer↓

Someone that generates and provides electricity and consumes it.

Renewable Energy Devices↓

REDs are microrenewable devices or renewable energy equipment and machinery that are embedded in the electrical and energy infrastructure. From solar photovoltaic to solar thermal to heat pumps, hydrogen fuels cells and the like. Solar thermal and heat pump REDs do not generate electricity but use electricity to transfer solar energy in the air, ground and water and indirectly and directly from the sun into heat. And in the form of solar thermal heat (infrared rather than light) sunshine is converted into useful heat to heat hot water and swimming pools mostly at the moment - but which can also be used to heat homes.

Future technology may well enable excess thermal energy to be converted into electricity. Solar Thermal Renewable Energy Devices offset energy that would otherwise be required so can also be seen in the role of energy conservation, like insulating a house (we use less energy or need to generate less energy as a result, so in the greater scheme of things are extremely useful devices).

Security of Supply↓

On-island secure power supply is the surest way to create energy independence and energy security. One of our aims is to create a grid resilient secure supply of power for the Island with the ability to maintain long-term storage from a combination of batteries and hydrogen. Strategic secure supply of power is important for critical businesses and for islands such as Guernsey. How resilient is a cable link? Cable links are useful for importing energy on occasions when we may have on-island shortfalls, but more important for export purposes, this reason being more economically and financially attractive than about security. It provides a different type of security.

Grid Resilience↓

Our homes and businesses are connected to the ‘grid’ - the criss-cross of wires and cables that connect us all together under the moniker infrastructure. This grid has a mixture of all types of equipment connected to it switching on and off all the time, from fridges to kettles, to industrial machinery, heat pumps, electric boilers and air-conditioning units. There is a specification for grid voltage and power factors.

As this equipment is constantly moving the grid voltage and current flows is constantly fluctuating. This has to be managed by the electrical energy supplier. For many years the minor voltage swings across the island have been tolerated by equipment and user alike. However, there have already been changes as more and more electric heating replaces oil and gas with bigger loads and sharper spikes. This has partly been managed by removing the timed low and high rates for electric heating, smoothing out the consumption, though much more could be done with better control systems at point of use. As more and more microrenewables and embedded generation come on line, the peaks and troughs will be more extreme. Imagine it’s a cloudy day and suddenly the sun comes out and every single solar PV comes into action flooding the grid. Then a big cloud flies over and blanks the solar, and it quickly reduces. How do we manage to retain grid resilience in that case? Voltages could drop quickly or rise above their specification, playing havoc with appliances and computers. Spikes and transients may occur.

There are several solutions:

• Every solar system installed should also include battery storage alongside, providing a local buffer, inhibiting peaks and drops.
• This would apply to homeowners, businesses and industrial suppliers.
• Hydrogen gas production can also deal with changing grid power taking up the peaks.
• Ultracapacitors can deal with fast-changing transients and spikes smoothing out the voltage and power factor.
• Utility-scale battery stores such as flow batteries, lithium-ion and others can act as large energy reservoirs, taking up peaks and providing large energy supplies when there is a shortfall.

Offshore Energy↓

The energy that is generated ‘off shore’ in and over the sea, within our territorial waters the maritime boundaries, which extend 12 nautical miles or approx. 22.22km. This could be wind energy, tidal energy or wave energy, or even solar energy. The amount of energy that could be generated is vast and could be used for a combination of things from exporting to mainland Europe, powering Guernsey, charging batteries, or making hydrogen from seawater.

The Bailiwick islands, and therefore their territorial jurisdictions, are independently governed. And so retain effective ownership over their respective territorial limits. This means that Guernsey cannot undertake operations in Alderney waters without permission (such as exists for fisheries protection for example) and vice versa. But similarly, Guernsey does not need permission from Alderney and Sark to undertake a development within our territorial waters and vice versa (subject of course to other best practice regarding stakeholder engagement and any other international obligations). Here at Renew Guernsey we think it would make sense for all the Bailiwick islands to work together on a collective Green Industrial Business Strategy which would be mutually beneficial economically.

Onshore Energy↓

Generating power onshore or on-island. Generally this is going to be solar photovoltaics, solar thermal collectors, and battery stores. Guernsey does have a small number of potential hydroelectric resources and there some potential for small wind devices in the right location – and as long as not visually detrimental - in the region of 10 to 15kW.

UPS↓

Uninterruptible Power Supplies maintain critical supplies in the home or business in case of a power outage. Certain circuits or all electrical circuits can make use of standby power. Usually, items like computer equipment or strategic lighting is kept in operation if the power goes out. UPS arrangements are critical for large businesses with server rooms or telecommunication and internet businesses.

Energy Conservation↓

Often coined the ‘fifth fuel’ because it can save as much as you generate. By more efficient equipment, more efficient control systems, using LED lighting and insulating homes and businesses, less energy is required in the first place. Rather than 30 solar panels to power an electric boiler you will need 10 solar panels. If the home is better insulated, then you might need a smaller heat pump and 6 solar panels to power your heat pump. The less energy is used and conserved, the lower the capital expenditure (capex) to generate renewable power.