• 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 over 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 PV 2.16kw (8 modules) Solar Thermal 4m 2 • • Installed cost approx. € 3,000 Installed cost approx. € 3,500? • • No maintenance Requires glycol change bi-annually • • Saving approx. € 160 per annum Saving approx. € 70 per annum ( € 243 with 9c feed in tariff / hot • water option) Stagnation while on vacation • • Works while house unoccupied Likely failures in pumps, expansion vessel and insulation • Solid state – no moving parts to fail
Monocrystalline module 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 Photovoltaic effect 3-11
Polycrystalline module • 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 Photovoltaic effect 3-12
All black (black back sheet) • 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 Photovoltaic effect 3-12
Dimensions • Most common panels are approx. 1650mm x 992mm • Can be mounted in portrait of landscape format
Electrical Characteristics • At 800W/m 2 , 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) Module current (A) U MPP voltage range Module voltage (V) Photovoltaic effect 3-15
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 optional 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 Wall mounted String – vs- Micro-inverters String Inverters Micro Inverters Advantages Advantages • • Inverters mounted on panel 1 inverter only required for each • Each inverter has its own MPPT system * • Typically mounted within easy inverter • Overcomes issues where access of end user • shading is concerned Data available on screen Drawbacks Drawbacks • • Shading needs to considering Power electrics more prone to when locating on roof failure due to weather • DC cabling in the dwelling considerations • Replacement on roof, even if covered by warranty, is more expensive * However larger systems may use a number of inverters as required
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 850W Nothing on
1400W 600W 2000W
500W 600W 100W
400W ZZZzzz … 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 of attaching to rafters rather than battens
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