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05/05/2019

Photo-Voltaic Solar Panels

BES – CA 03

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KEVIN MARTIN

G00255242

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Contents List of Figures ............................................................................................................................. ii

References ................................................................................................................................ iii

Introduction - What is Solar Power? .......................................................................................... 1

What are Photo-Voltaic Solar Panels? ....................................................................................... 1

Sunlight to Electricity – How Panels Work ................................................................................. 3

Types of Solar PV Panels ............................................................................................................ 3

1. Monocrystalline .............................................................................................................. 3

2. Polycrystalline ................................................................................................................. 4

3. Amorphous or Thin Film ................................................................................................. 4

How Much Electricity Will Solar Panels Generate? ................................................................... 4

Do I Need Planning Permission to Install Solar PV? ................................................................... 4

Typical Installation ..................................................................................................................... 5

Is There a “Feed-In Tariff” Payment for Excess Electricity? ....................................................... 5

What About Battery Storage? .................................................................................................... 6

Grants & Incentives .................................................................................................................... 7

What Does It Cost to Buy and Install a PV System? ................................................................... 8

How Much can I Expect to Save & What is the Payback Period? .............................................. 9

Installation to the Retrofit Dwelling ........................................................................................ 10

Results ...................................................................................................................................... 11

Conclusion ................................................................................................................................ 13

List of Figures Figure 1 - Construction of a PV Cell ........................................................................................... 1

Figure 2 - From Cell to Array ...................................................................................................... 2

Figure 3 - Structure of a Typical Mono-Crystalline PV Solar Panel ............................................ 2

Figure 4 - How PV Solar Panels Work ........................................................................................ 3

Figure 5 - Typical Solar PV Installation ....................................................................................... 5

Figure 6 - Tesla Powerwall ......................................................................................................... 6

Figure 7- BER rating Post Retrofit ............................................................................................ 10

Figure 8 - DEAP Results Post Retrofit ....................................................................................... 10

Figure 9- DEAP Results Post Retrofit - Bar Chart ..................................................................... 11

Figure 10 - DEAP Results Post PV Installation .......................................................................... 12

Figure 11 - - DEAP Results Post PV Installation - Bar Chart ..................................................... 13

Figure 12 - BER Rating Post PV Installation .............................................................................. 13

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References Commissioners, D. o. (2019). HRI for Homeowners and Landlords. Retrieved from

www.revenue.ie: https://www.revenue.ie/en/property/home-renovation-

incentive/hri-for-homeowners-and-landlords/index.aspx

Davis, L. a. (n.d.). Spon’s Architects’ and Builders’ Price Book. 1998: Spon Press.

Department for the Environment, H. a. (2008). S.I. No. 235 of 2008. Statutory Instruments

No. 235 of 2008. Ireland: GOVERNMENT PUBLICATIONS.

Department of Housing, Planning, Community and Local Government. (2017). Technical

Guidance Document L - Conservation of Fuel and Energy - Dwellings. Building

Regulations 2011 - Technical Guidance Document L - Conservation of Fuel and Energy

- Dwellings. Dublin, Ireland: GOVERNMENT PUBLICATIONS.

Deptartment for the Environment, H. a. (2007). S.I. No. 83 of 2007. Statutory Instruments

No. 83 of 2007. Ireland: GOVERNMENT PUBLICATIONS OFFICE.

Government, D. f. (2001). S.I. No. 600 of 2001. Statutory Instrument No. 600 of 2001.

Ireland: GOVERNMENT PUBLICATIONS.

Ireland, E. (2017). Electric Ireland Breaks New Ground With Launch Into Residential Solar PV

Market. Retrieved from www.esb.ie: https://www.esb.ie/tns/press-

centre/2017/2017/04/12/electric-ireland-breaks-new-ground-with-launch-into-

residential-solar-pv-market

Irish Solar Energy Association. (n.d.). www.irishsolarenergy.org/solar-energy. Retrieved from

www.irishsolarenergy.org/: https://irishsolarenergy.org/solar-energy

Review, M. T. (2009). Solar Power Will Make a Difference Eventually. Retrieved from

www.technologyreview.com: https://www.technologyreview.com/s/414792/solar-

power-will-make-a-difference-eventually/

SEAI. (2019). Community Grants. Retrieved from www.seai.ie:

https://www.seai.ie/grants/community-grants/

SEAI. (2019). Deep Retrofit Grant. Retrieved from www.seai.ie:

https://www.seai.ie/grants/home-energy-grants/deep-retrofit-grant/

SEAI. (2019). Solar Electricity Grant. Retrieved from www.seai.ie:

https://www.seai.ie/grants/home-energy-grants/solar-electricity-grant/

Solartricity. (2019). Part L Building Code Design. Retrieved from www.solartricity.ie:

https://solartricity.ie/design-your-system-quote/part-l-building-code-design/

Solartricity. (2019). Power Production Estimator. Retrieved from www.solartricity.ie:

https://solartricity.ie/design-your-system-quote/power-production-estimator/

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Introduction - What is Solar Power? Solar power is radiant energy from the sun. It will always be our greatest safe source of

constant and reliable clean renewable energy for the world’s population. The sun delivers

more energy to Earth in one hour than humanity consumes over the course of a year, making

solar the only renewable energy source that can keep up with global demands. (Review,

2009) Due to the advancements in technology it is now possible harness this solar power to

generate electricity and heat water. The main advantages are that it is FREE AND

SUSTAINABLE. Solar energy also avoids the politics and price increases that are associated

with fossil fuel. Solar PV is silent, robust, reliable, no moving parts and no emissions. Of all

electricity generation methods, solar energy has the least environmental impact. Over a 25

year lifetime, for every square metre of solar PV panel, approximately 1,500 kg of CO2

emissions will be prevented. This includes the CO2 emissions avoided by exported energy.

(Davis)

What are Photo-Voltaic Solar Panels? Photo-Voltaic Solar Panels is a renewable energy system which converts light into electricity

by using photovoltaic modules, generally on the roof of a building. (“Photo” meaning light

and “Voltaic” coming from the electric Volt.) The solar cell is the main component consisting

of one or two layers of a semi-conductor and these cells convert solar radiation, not heat,

into direct current electricity. (Refer to Fig. 1) As irradiance, sunlight, increases the power

output increases. PV cells are more commonly based on silicon.

Figure 1 - Construction of a PV Cell

Source: www.samlexsolar.com

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The solar cells are wired together and sealed in an environmentally protective laminate to

form a module. Modules assembled in parallel as a pre-wired installable unit become a solar

panel and then an array, the complete power-generating unit, is formed by connecting

panels together. (Refer to Fig. 2)

Figure 2 - From Cell to Array

Source: www.solardirect.com

The module is enclosed in a transparent sheet on the front surface, usually tempered glass,

and a protective waterproof backing sheet, usually plastic. An aluminium frame to the edges

holds everything together in a mountable unit ready to be fixed to a structural support

frame. (Refer to Fig. 3) PV systems are most efficient when they have the same orientation

and tilt for all modules, similar module and cell types and sizes, uniform temperature

conditions etc.

Source: www.samlexsolar. com

Figure 3 - Structure of a Typical Mono-Crystalline PV Solar Panel

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Sunlight to Electricity – How Panels Work During daylight hours, photons (sunlight) fall on the solar PV panels. The panels convert the

photons into electrons of direct current electricity which is sent to the inverter and

associated control and protection equipment. The inverter converts the direct current into

alternating current, a process sometimes referred to as “conditioning the power”. The

building uses AC electricity from the solar panels first, with any additional demand supplied

from the grid. Solar energy systems produce a very clean high-quality electricity lacking in

fluctuations, which otherwise would damage electronic equipment.

Source: www.enviroheatnw.co.uk

Types of Solar PV Panels There are 3 types of PV solar panels:

1. Monocrystalline Monocrystalline cells are cut from a single crystal of silicon. These are the oldest, most

efficient type of cell and also the most expensive production technique. (Refer to Fig. 3)

Encased units mounted on a structural frame. Module efficiency averages about 10% to

12%.

Figure 4 - How PV Solar Panels Work

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2. Polycrystalline Polycrystalline cells consist of many crystals sliced from a block of silicon. They are

slightly less efficient and cheaper than monocrystalline cells. Encased units mounted on

a structural frame. Module efficiency averages about 10% to 11%

3. Amorphous or Thin Film Amorphous cells are manufactured by vaporising non-crystalline silicon and then

depositing it on various surfaces including stainless steel or glass. This is the cheapest

least efficient type of PV panel and power output dissipates over time. It can be

manufactured on a flexible surface. Module efficiency averages 7% to 8%

Module efficiencies vary from manufacturer to manufacturer, always check the relevant

accurate conversion efficiency.

How Much Electricity Will Solar Panels Generate? PV systems are rated in kilowatt peak (kWp) which relates to the combined potential

capacity of the entire array installed and operating under prime conditions. The six main

factors that impact energy generation of a Solar Photo-Voltaic system are:

• Efficiency of the panels.

• The Peak Power rating of the array.

• Efficiency of the inverter.

• Transmission losses.

• Overall size of the array.

• Latitude of the location.

• Orientation of the panels.

• The pitch of the panels.

• Overshading.

A solar PV system that is installed facing due south at an angle of 30⁰ and is unshaded

should operate at optimum efficiency.

Each installed kWp can be expected to produce around 850kWh (units) of electricity per year

in the Ireland. A 2kWp system would thus produce approximately 1,700kWh / year, around

half of the annual electricity consumption per average household. (Irish Solar Energy

Association, n.d.)

Do I Need Planning Permission to Install Solar PV? In general, a 10-panel system or smaller that does not cover more than 50% of the total roof

area is deemed exempted development. Local authority planning offices should be

contacted in the early design stages so that any local planning issues can be dealt with

quickly.

• Statutory Instruments (S.I.) No’s. 83 of 2007 and 235 of 2008 outlines PV installations

on domestic premises and agricultural / business / commercial premises respectively

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that are exempted development. (Deptartment for the Environment, 2007)

(Department for the Environment, 2008)

• Statutory Instrument No. 600 of 2001, outlines where solar PV are not exempted

development. (Government, 2001)

This translates into a PV system under 12m2 for a domestic house being exempted

development and not requiring Planning Permission i.e. a PV system equivalent to approx.

2kWp.

Typical Installation The sizing of a PV system can vary on consumer requirements and roof size. In general, a 1.8

kWp system covering a 10 m2 area will suffice for a domestic installation. This size of an

installation will produce approx. 1,400 kWh/yr in electricity. An Irish household’s electricity

use is on average 4,200 kWh/yr. PV panels of this scale will typically improve a Building

Energy Rating by one grade e.g. B3 to B2.

A 1.8 kWp array will usually consist of 6 by 300w panels with a lifespan of 25 years and no

maintenance. The invertor is the exception, having to be replaced after 15 years. The panels

are self-cleaning once installed at a pitch of 5 degrees or more. (Refer to Fig. 5)

Source: www.energywiseireland.ie

Is There a “Feed-In Tariff” Payment for Excess Electricity? In Northern Ireland any electricity not used by the consumer is exported to the grid with the

added benefit of a “Feed-In Tariff” Payment. While in the Republic of Ireland, any surplus

electricity must be stored in a battery or possibly, with the use of a diverter, sent to your hot

water cylinder (immersion). Currently there is no “Feed-In” Tariff payment available despite

continuous public pressure. In the future, EU directives may change this.

Figure 5 - Typical Solar PV Installation

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What About Battery Storage? One problem with solar energy is that electricity is not always produced when you need it

e.g. lighting at night. The solution is to provide battery storage that will feed back into your

home when you need it i.e. evening/night. During the day, the system detects when the

panels are producing surplus electricity and has begun to feed back into the grid. It will then

begin to store the extra energy in the connected battery storage. Historically this tended to

be a large bank of lead acid cells which were extremely expensive.

Factors to consider when choosing domestic batteries:

• Lifespan i.e. the number of discharge/charge cycles

• Power output and capacity

• Installation cost.

Lithium ion is the latest in battery technology but the environmental and social costs of

producing them negate the positives. For example, Tesla have developed the Powerwall

storage system. This battery system when coupled with sufficient solar PV panels, can

provide for all the daily household electricity requirements. Costs for a Powerwall battery

for an average home is €7,100. (See Fig.6)

Figure 6 - Tesla Powerwall

If adequate storage technologies become available, cheap solar power would become the

norm. Covering 1.7 percent of the United States’ land area with solar collectors operating at

an efficiency of 10 percent would supply three terawatts of power, enough to meet

America’s energy needs, according to Nate Lewis, a chemist at Caltech. (Review, 2009)

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Hydrogen fuel cells are a new emerging technology that can store and transport

renewables-generated electricity.

Grants & Incentives Current Building Regulations, Part L for Dwellings, states that new homes must be NZEB

compliant. This includes a Maximum Energy Performance Coefficient (EPC) of 0.3, a

Maximum Carbon Performance (CPC) of 0.35 and a Renewable Energy Ratio (RER) of 20%.

(Department of Housing, Planning, Community and Local Government, 2017) Solar PV

systems can provide the 20% RER requirement. This is the main reason and incentive for the

current uptake of solar PV systems.

Here are four examples of funding streams available to help reduce the purchase and

installation costs of the solar PV system:

• Domestic Solar PV Grant: At the moment, there is a grant available to homeowners

towards the cost of installation of a domestic solar PV system from the SEAI.

Grant available: €700 per kW up to 2 kW system. If a battery system is installed, then

€700 per kW up to 4kW and €1000 for the battery system.

Full details of this grant can be found on the Solar PV Grant webpage. (SEAI, Solar

Electricity Grant, 2019)

• Home Renovation Incentive: The Home Renovation Incentive is a relief from Income

Tax that can be claimed as a 13.5% tax credit for repairs, renovations and

improvements over €4,405 (before VAT) to your property. Some home solar PV

systems will be eligible. Refer to the following examples.

Full details of this grant can be found on the Revenue webpage. (Commissioners,

2019)

• Deep Retrofit Pilot: The scheme requires the homeowner to undertake extensive

improvements in order to achieve an A-rated home. Measures include insulation,

upgrading windows and doors, improving air tightness and ventilation. SEAI’s Deep

Retrofit Pilot can provide grants up to 50% of costs for solar PV when installed as

part of the upgrades.

Full details can be found on the Deep Retrofit Pilot Programme webpage. (SEAI,

Deep Retrofit Grant, 2019)

• Better Energy Communities: This program applies to communities that are engaging

in energy efficiency upgrades or retrofits as an integral group. SEAI’s Better Energy

Communities can provide grant support to these projects for the installation of solar

PV systems as long as they are part of a larger energy efficiency upgrade

strategy/project.

Full details can be found on the Better Energy Communities webpage. (SEAI, 2019)

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What Does It Cost to Buy and Install a PV System? The cost of solar PV panel systems has dropped dramatically over the last 10 years. As with

everything, the price will vary depending on system chosen, size, supplier, installer,

accessibility of roof or site etc. A broad guide is €1500-2000 per kW installed (ex VAT).

See quotes below as examples/benchmarks.

Supplier 01 (Electric Ireland)

7 x 270w: €3,435 +VAT including diverter

6 x 300w: €3,615 +VAT including diverter

2.5 kWh battery €6k extra

Supplier 02 (Alternative Energy Ireland):

7 x 300w: €5,260 +VAT

Battery approx. €2k extra

Supplier 03 (SEAI listed)

8 x 275w: €4.5k

300w panels €35 extra per panel

€450 additional for diverter

Supplier 04 (Not SEAI listed)

4 kw PV Array with 3.6kw Hybrid Inverter and 5kWh Battery €9000 +VAT

With EDDI diverter €9500 +VAT

For the purposes of this report Supplier 01, Electric Ireland, has been chosen.

6 x 300w panels and a diverter for €3,615 excluding VAT, with the additional benefit of an

offer of 20% deposit and 36 monthly interest free payments, this option is very attractive.

They also provide a custom-built app that shows energy savings in real-time.

Based on these prices:

€3,615 + 488 (13.5% VAT) = €4,103

€4,103 – 1,200 (SEAI grant) = €2,843

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Home Renovation Incentive (HRI)

If you receive a grant for qualifying work then the total qualifying expenditure will be

reduced by three times the grant amount. (Commissioners, 2019)

€4,103 Solar PV System

€1,200 SEAI grant

Reduced by three times SEAI grant received €1,260 x 3 = €3,780.00

Qualifying expenditure (includes VAT at 13.5%) €323.00

Total qualifying expenditure (amount without VAT) €284.58

Total tax credit to be received €284.58 x 13.5% = €38.42

Nett Expenditure = Cost – ( SEAI grant + HRI )

= 4,103 – ( 1,260 + 38.42 )

= €2,804.58

How Much can I Expect to Save & What is the Payback Period? According to Electric Ireland the following savings can be achieved by installing a 6 panel

Solar PV system operating in optimum conditions:

Cork €253.00 per year (1610kWh)

Kildare €239.00 per year (1520 kWh)

Clonmel €232.00 per year (1480kWh)

Claremorris €226.00 per year (1440kWh)

This calculation is based on 85% of power generated being used in the household @18.5c

per kWh. (Ireland, 2017)

Based on the chosen system from Electric Ireland, assuming there is no increase in the cost

of electricity and taking the savings based on a dwelling in Claremorris:

Nett expenditure (From above) = €2,804.58

Assumed savings per year = € 226.00

Payback Period = (2804.58/226)

= 12.41 years

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Installation to the Retrofit Dwelling The dwelling house used in the Retrofit Project has a BER of C1 post retrofit. (Refer to Fig.7)

There are no renewables installed or considered in this rating. If the proposed system is

installed, what affect will they solar PV array have?

Source: DEAP Software

The following results were achieved post retrofit by the dwelling:

Figure 8 - DEAP Results Post Retrofit

Source: DEAP Software

Figure 7- BER rating Post Retrofit

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Figure 9- DEAP Results Post Retrofit - Bar Chart

Source: DEAP Software

The following on-site details will affect solar PV performance:

1. The roof faces south-west

2. Pitch of the roof is approx. 45˚

3. There is no overshading

Based on these factors, in order to meet Part L renewable energy requirements, the house

will need a system with a peak output of at least 404 W. (Part L Calculator) (Solartricity,

2019)

To comply 2 x 300W panels from our selected system is sufficient but to maximise our

savings through grants, supplier promotions and electricity production a 6 x 300W system

will be installed. Estimated output for the house array according to SEAI standards is 1447

Kw Hrs per year. (Power Production Calculator) (Solartricity, 2019)

Results As a result of the installation of the solar PV array, the dwelling now more than complies

with the Renewable Energy Ratio (RER) requirements of 20%. (Refer to Fig. 10 & 11)

There is an overall reduction in

• Delivered Energy 1447 kWhr/yr

• Primary Energy 3169 kWhr/yr

• Carbon Emissions 684 Kg/yr

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Figure 10 - DEAP Results Post PV Installation

Source: DEAP Software

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Figure 11 - - DEAP Results Post PV Installation - Bar Chart

Source: DEAP Software

The BER rating has improved to a B2. (Refer to Fig.12)

Figure 12 - BER Rating Post PV Installation

Source: DEAP Software

Conclusion The conclusions from this report are as follows:

1. Various technologies can be installed or retrofitted to comply with the Renewable

Energy Ratio (RER) requirements of 20% but Solar PV arrays are the easiest to

retrofit and installation is generally less than a day on a regular dwelling.

2. Addition of a solar PV array will improve the dwelling’s BER considerably. In the

Retrofit example, an improvement of 2 grades was observed.

3. Currently the payback period is slightly smaller than the lifetime of the inverter, 15

years, and the nett savings overall are minimal. Based on present costs, incentives

and savings, typically solar PV arrays do not have a financial advantage. At a point

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when there is a feedback tariff in Ireland, this may change. The costs are reducing

year on year which, in time, with a feedback tariff will create an attractive payback

period.

4. NZEB is now a compulsory requirement and in non-domestic buildings solar PV is

coupled with heat pumps to achieve the RER requirement.

Finally, Solar PV is an environmental choice and with Ireland being the second country in the

world to declare a “Climate Emergency”, every household needs to play their part. Solar PV

farms would dramatically help in our Kyoto & EU environmental requirements, which we are

not going to meet, but without a commercially attractive feedback tariff the private sector is

slow to invest in this sector.

Why settle for the bare minimum? The target should be nett zero not near zero.