www.solartricity.ie Office / Tech Support: 01 864 3721 Quentin: - - PowerPoint PPT Presentation

• Introduction to Photovoltaics
• Component Parts
• Panels
• Mountings
• Electronics
• System design;
• For Part L
• For Energy Production
• DEAP
• Planning

www.solartricity.ie

Office / Tech Support: 01 864 3721 Quentin: 086 869 3140 quentin@solartricity.ie

Solar PVs

• Photons cause electron flow across

junction between two types of silicone

• Process degrades at rate of about 0.7%

per annum

• Commercial efficiency typically 16%
• Complements wind as part of national

renewable energy

• Initially developed for remote power

(satellites, then lighthouses) – Over 50 years in use

• Massive price decreases as volume

production rises

Charanka Solar Park

550Mw 3km from end to end 2,750,000 Panels

Charanka Solar Park

But solar parks don’t have economy of scale

• ver industrial roof

installation Quite the opposite. Require grid and security and use land resources

Solar Thermal – the truth about savings

• Typical 4m2 system with 200L cylinder produces 1810 KwHrs/yr

(source T-Sol™ based on Gasokol Austrian panels)

• Cost using off-peak electricity or oil @ 9c = €163 /yr
• Glycol must be changed very 2-3 years at cost of €200-€300
• Savings after servicing €63 per year
• Moving parts, pump stations, insulation and expansion vessels

require replacement over time

• Stagnation protection often not satisfactory for summer vacation

Solar PV –vs- Solar Thermal

Solar Thermal 4m2

• Installed cost approx. €3,500?
• Requires glycol change bi-annually
• Saving approx. €70 per annum
• Stagnation while on vacation
• Likely failures in pumps, expansion

vessel and insulation Solar PV 2.16kw (8 modules)

• Installed cost approx. €3,000
• No maintenance
• Saving approx. €160 per annum

(€243 with 9c feed in tariff / hot water option)

• Works while house unoccupied
• Solid state – no moving parts to fail

Monocrystalline module

3-11 Photovoltaic effect

• Cut from solid silicon rods with

round edges removed. Hence appearance

• Longer established (since 1948),

therefore longevity established

• May have slightly lower output in

low-light, but better at high temperature

Polycrystalline module

3-12 Photovoltaic effect

• Tends to have less of the blue

tinge in modern production

• Can come on white or black

back-sheet. White is more efficient due to better heat loss

• Can be black or natural

aluminium frame. Black usually more discreet

• First manufactured 1982

All black (black back sheet)

3-12 Photovoltaic effect

• Black back sheet so white triangles are not

conspicuous

• White is more efficient due to better heat

loss, but black more aesthetically acceptable

• Can be black or natural aluminium frame.

Black usually more discreet but powder coating pushes up price

Dimensions

• Most common panels are
• approx. 1650mm x 992mm
• Can be mounted in portrait of

landscape format

Electrical Characteristics

• At 800W/m2, 73% of 1kw

production

• Note Isc at 800W/m2 is less

than Imp at 1kw

• Therefore fuse protection on

single string is not possible, (nor necessary)

Industrial Systems

String Combiners / Fuses Multiple Strings can produce higher current in short circuit

In > 1.5 x Isc stc In ≤ 2.4 x Isc stc In ≤ Maximum series fuse value Fuse both +ve and -ve

Industrial Systems

String Combiners / Fuses Can use string combiner boxes to implement double pole fuse

Effect of irradiation levels

Unlike thermal, output is almost pro-rata to light levels therefore less seasonal Inverter tracks maximum power point (MPPT Tracking)

3-15 UMPP voltage range Module voltage (V) Module current (A) Photovoltaic effect

Standards

MCS in UK.

• UK Micro-generation Certification Scheme, pre-requisite to feed in tariff
• Sets standards for major components and for installation practice

TUV tested Standards Required

• EN 61215 - Energy Production (or EN61646 for Thin Film)
• EN 61730 - Mechanical Safety
• EN 62716 – Ammonia Corrosion Testing
• EN61701 – Salt Mist Corrosion Testing

DEAP Manual: Requires EN 61215 cert on file

Bloomberg Tier 1 List as an industry standard

Bloomberg Tier 1 List as an industry standard

Layout 8 panel dual-tracking system for partial shading or East/West

Part B Compliance

“Where Photovoltaic (P.V.) panels are provided on buildings, provision should be made for the isolation of the panel array externally in accordance with ET101, 2008”.

• Fire Switch disconnecting PV array
• Panel Optimisers
• Micro Inverters

Part B Compliance

Inverters

• Injects DC from panels into grid
• Must conform to EN50438
• Unique Irish variants
• Usually under-sized slightly for

improved efficiency

• May include DC isolator
• Most also offer wifi connectivity as
• ptional extra

MCS on Power ratio - It is common practice for an inverter power to be less than the PV array

• rating. In the UK, inverters are typically sized in

the range of 100 - 80% of array capacity.

Inverter comparison

• Inverters mounted on panel
• Each inverter has its own MPPT

inverter

• Overcomes issues where

shading is concerned

Wall mounted String –vs- Micro-inverters

• 1 inverter only required for each

system *

• Typically mounted within easy

access of end user

• Data available on screen

* However larger systems may use a number of inverters as required

String Inverters

Micro Inverters Advantages Advantages

• Shading needs to considering

when locating on roof

• DC cabling in the dwelling
• Power electrics more prone to

failure due to weather considerations

• Replacement on roof, even if

covered by warranty, is more expensive Drawbacks Drawbacks

Optimised Panels

• Performs MPPT on each

panel individually

• No power electronics, so

risk of failure remote

• Covered by panel

manufacturers warranty

Remote Monitoring Options.

Relatively low cost €50 to €100 per system

Inverter – Irish Standards

Partial Shading – less of a problem with Landscape format due to layout of bypass diodes

Cabling Options

MCS Standard: Double-insulated cable can be used within the loft space or in open spaces. If routing DC cables hidden in walls, should use SWA (steel wire armoured) cables for DC and use two DC isolators

DC Isolator

• Disconnects panels from

inverter

• No other connections should

be broken or made while this connector is closed

Labelling Requirements

Labelling Requirements

MCB

• Usually an MCB in the consumer unit
• Feeds local grid via consumer unit and surplus exported
• Generally no RCD required RCD may produce false tripping

however where required consider 100ma

Lightning

• Generally accepted that the installation of a typical roof-mounted PV system

presents a very small increased risk of a direct lightning strike.

• Not necessarily the case where
• the PV system is particularly large,
• where the PV system is installed on the top of a tall building,
• where the PV system becomes the tallest structure in the vicinity, or
• where the PV system is installed in an open area such as a field

850W Nothing on 850W

600W 2000W 1400W

600W 100W 500W

ZZZzzz… 400W 400W

Immersion Diversion Units

Immersion Diversion Units

• Typical solar thermal system will delivery 1800 KwHrs of hot water per annum
• Typical solar PV 2kw system will deliver 1900 KwHrs of POWER per annum
• If 33% of this is used as electricity, saving is 19c per KwHr on that portion

Remaining 66% diverted to heating water will save approx 9c per KwHr.

• Immersion diversion would cause de-rating of the system under DEAP so

technically, can only be fitted as a retrofit

• Viable alternative to export tariff until this returns
• Only really viable for systems above about 1.5kw
• Issues with electrical noise on some models

Applying for Connection for PV Inverter

• Complete form NC6 or for new dwelling, inform ESB of the size of inverter which

will be used

• Provide EN50438 certificate for inverter (with Irish Variants)
• Industrial systems (over 6kw) require Mainspro or similar relay

http://www.esb.ie/esbnetworks/en/commercial-downloads/NC6.pdf

Battery Options

• Typical battery costs currently €420 per KwHr (ie

€2000 for 4.8kw hr

• 5kwHr/day saves 90c
• = €3285 over ten years life of battery (if you could

cycle all 4.8kw Hrs

• Worth considering if UPS is required for security of

supply (freezers, servers etc.)

Roof Mounting

European Batten Hooks

• Secured only to battens.

Depend on uplift strength of Paslode nails.

• Max uplift much lower

requirement in EU – may not survive winds in Ireland and Scotland

• Safer to adopt industry norm
• f attaching to rafters rather

than battens

Roof Hooks & Rail Systems

• Because of wind loading, roof hooks

should be fixed directly to rafters

• Agrement now suggestes parallel

timbers

• Roof hooks will deflect, so should have

no contact with any slates or tiles

• Observe max space between roof hooks
• Typically 80 to 120cm
• May have wider spacing in centre of

array

• Depends on manufacturers specs

and wind load

• Rail can overhang hooks by 20 to 30cmm
• Rails may be joined and joiners do not

reduce loading

Roof Hook Flashing

Roof Hook Flashing

Roof Hook Flashing

Roof Hook Flashing

Wide hooks for roof tiles

Solar Slate Plate for Retrofit

Typical Rail Spacing

Roof Integrated

Benefits

• Less visual impact
• Lower wind exposure
• Easier site management

Disadvantages

• Higher installation cost

(partly offset by reduced slates)

• Slightly reduced output

due to higher temperature

Trapezoidal Steel

Corrugated Steel Trapezoidal Steel

• Very low-cost industrial

systems

• As little as 4c per watt
• Very quick to fit
• Mounting screws self—drilling

to form rivet

• Zinc screw has sacrificial

cathodic effect

Standing Seams

Various fittings to attach rails to standing seams

Industrial Systems

• Often better payback as displacing all

power at retail price

• Use monitoring in advance to assess

base-load Potential Use

• Super-Valu and similar supermarkets
• Hotels
• Industry
• Anywhere with environmental

credentials to maintain

Utility Company Monitoring

Half-hourly data may not have sufficient granularity

Industrial Systems

East/West

• Quick assembly, low wind loading, ready ballasted
• Faces east and west at 10O pitch
• Full wind load data available

Small Flat-Roof Systems

Modular plastic ballasted mountings

Industrial Flat Roof Systems

Low ballast clicklock modules

Industrial Flat Roof Systems

Low ballast clicklock modules

Industrial Systems

East/West

• South facing 30O pitch optimal for yearly production
• Lower pitch is often used to reduce wind load and mounting cost
• South facing 4kw system at 30O slope produces 3976 KwHrs/yr
• South facing 4kw system at 15O slope produces 3751 KwHrs/yr (6% loss)
• East-west facing 4kw system at 10O slope produces 3319/Kwhrs/yr (16%

loss)

• Losses can be compensated with additional panels for lower cost than

through-roof mounting required for optimum pitch

Simulation Software

For larger commercial systems, simulations can be prepared using PV-Sol™ or PV-Syst™

Simulation Software

250KwP system 15o pitch facing SSW, Dublin

Industrial Systems

System Design for Part L

Technical Guidance Document Part L 2011

• 10 kWh/m2/annum contributing to energy use for domestic

hot water heating, space heating or cooling; OR

• 4 kWh/m2/annum of electrical energy;

OR

• a combination of these which would have equivalent effect.
• By far the lowest capital cost to Part L Compliance
• Scalable - especially on larger houses

System Design for Part L

Technical Guidance Document Part L 2011

1.2.1 …The following represents a reasonable minimum level of energy provision from renewable energy technologies in order to satisfy Regulation L3(b): -

• 10 kWh/m2/annum contributing to energy use for domestic hot water heating,

space heating or cooling; or

• 4 kWh/m2/annum of electrical energy; or
• a combination of these which would have equivalent effect.

Electricity has a higher primary energy value than heat, hence reduced requirement PROCEDURE: Calculate system to meet renewables component Then check EPC & CPC for compliance If more energy required to meet EPC & CPC, scale up until all compliances are met

System Design – for Part L

• For example, house 150m2 will need to produce

600KwHrs electricity. Need to consider;

• Roof orientation
• Roof pitch
• Shading factor

System Design Part L

• Apendix M of DEAP Manual;

The electricity produced by the PV module in kWh/year is 0.80 x kWp x S x ZPV where S is the annual solar radiation from Table H2 (depending on orientation and pitch), ZPV is the overshading factor from Table H3.

• Take a system with three off 250W panels. Total panels = 750W or 0.75Kwp
• Lets assume house has pitch 30 degrees and roof facing SE.

Orientation & Pitch

0.80 x kWp x S x ZPV

• KwP = 0.75
• Roof pitch 30 degrees facing SE has S (solar radiation) = 1021 (KwHrs/m2/yr)

Shading Factor

0.80 x kWp x S x ZPV

• KwP = 0.75
• Roof pitch 30 degrees facing SE has S (solar radiation) = 1021 (KwHrs/m2/yr)
• Assume shading from Table H3 is “none or very little”. ZPV = 1

Calculation

Output is 0.8 x 0.75Kwp X 1021 X 1 = 612.6KwHrs/Yr. System meets renewables obligation of Part L for house 150m2 PvSyst suggests this system in Dublin would produce 675 KwHrs.

Calculation

Another formula

Panel size in Peak Watts = 4 x area in m2 / (S x Zpv x 0.8)

Online Part L Calculator

Online Energy Production Calculator

Entering in DEAP

Entering in DEAP

• Enter calculated production for both Part L contribution and Delivered Energy.
• Look up current value for Primary Energy Conversion Factor on SEAI website

(currently 2.19)

• Look up CO2 Emission Factor for electricity on SEAI website (currently 0.473)
• http://www.seai.ie/Your_Building/BER/BER_FAQ/FAQ_DEAP/Results/What_are_the

_electricity_factors_used_in_the_latest_version_of_DEAP.html

Apartment Blocks

DEAP Manual: In the case of a building containing more than one dwelling, e.g. a block of flats, then: a) if the PV output goes to particular individual flats, the annual output is credited to the flats concerned; b) otherwise the total electricity generated is divided amongst all the flats in the block in proportion to their floor area. In case a) an inverter is needed for each flat with a PV electricity supply. In case b) there will usually be a single inverter for the total PV array and the electricity generated fed to the landlord supply or to the distribution system for the flats (with provision for export of electricity generated in excess of instantaneous demand). Note the electricity supplied to common areas is not considered in the DEAP calculations

Apartment Blocks

Note that electricity supplied to common areas in a development is not considered in DEAP assessments. Statement from SEAI: The statement above in DEAP is relating to the common areas not being considered at all under the DEAP assessments. However, our understanding is that if some of the PV energy is to be used in common areas then this is subtracted from the total contribution to the apartment block before dividing the remainder amongst the apartments being assessed. We would advise you to double check this with DECLG (building standards section) for clarification.

Other ways of achieving Part L

Solar Thermal

• Some households use large amounts of hot water in summer, others use
• showers. (Most modern dishwashers and washing machines use electricity to

heat water not stored hot water)

• Maintenance of solar thermal required.
• Heat dump strategy required
• To cope with excess summer production / holidays
• Lack of heat dumps has given industry bad reputation
• Stagnation
• Puts pressure on component parts
• Degrades glycol

Heat Pumps

• may be justified if large amount of space heating required
• In a well insulated envelope, or near-passive, savings negligible and would not

be recouped in the lifetime of the system

• High power consumption
• High initial cost with limited life span 10-12 years leading to replacement by

the end user

Planning Exemptions

Solar PV or Solar Thermal panel in a domestic setting

• Total panel area must not exceed 12 sq. m or 50% of the total roof area including

existing panels

• The panel must be a minimum of 50cm from the edge of the wall or roof on which

it is mounted.

• A free standing array’s height must not exceed 2m above ground level.
• The erection of a free standing array must not reduce the area of private space to

the rear or side of the house to less than 25 sq. m. All assumes not in a visually sensitive area.

Planning Exemptions

Solar within a light industrial or business setting

• Can not be erected on a wall.
• Total panel area must not exceed 50 sq. m or 50% of the total roof area including

existing panels.

• The panel must be a minimum of 50cm from the edge of the roof on which it is

mounted or 2m on a flat roof.

• Any associated equipment or storage must be within the roof space of the building.
• A free standing array’s height must not exceed 2m above ground level.
• The total aperture area of a free standing array must not exceed 25 sq. m.
• No advertising can be placed on the panel and a free standing panel must not be

placed to the front of the premises.

Where is Solar PV going?

By the time the developments in planning are ready for use we expect….

• Feed in tariff in the region of 9-12c for generation
• 3-4c for exporting

We expect to see more and more focus on standards for compliance

• Module standards and expectations raised for efficiency and quality
• Inverters with interaction and monitoring
• Standards for mounting to exclude hanger bolts and move to roof hooks
• r integrated options

With all of this in mind we believe larger systems should be included for new houses in the region of 3-4kw for domestic and for industrial /commercial applications up to 500kw should be considered where the best use of the technology can be truly delivered

The Future

• Most other regions now have feed in or export tariff and Ireland will likely

follow suit in next year

• Houses under planning should include viable photovoltaic options in the

plans.

• Consider economic scale systems;

System 3 Panel 8 Panel 16 Panel Size 810W 2160W 4320W Hardware € 1,125 € 2,531 € 4,322 Installation € 400 € 450 € 600 Total € 1,525 € 2,981 € 4,922 Cost per Watt € 1.88 € 1.38 € 1.14

The Future

Typical Part L 3-panel systems

The Future

Estate with functional 3kw systems

The Future

Consider designing into the roof and Velux Windows Solar PV should now be designed in, rather than an afterthought

The Future

Use roof-integrated rather than on-roof

www.solartricity.ie

Office / Tech Support: 01 864 3721 Quentin: 086 869 3140 quentin@constructionpv.ie