The Emerging Electrical Markets for Copper
Solar Photovoltaic Electricity Generation
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Solar Photovoltaic Electricity GenerationSector BackgroundGlobal energy consumption is estimated to be around 470 EJ (exajoules) per year. The sun delivers to the earth almost 4 million EJ of energy. So, in theory, the sun could provide at least eight thousand times the energy we need. The difficulty is in finding ways to capture and store this energy, and convert it into a useable form. Solar technologies can be broadly characterised as either passive or active, depending on the way in which they capture, convert and distribute the sun’s energy. The primary active solar technology uses photovoltaic (PV) panels, pumps, and fans to convert sunlight into useful outputs, either electricity or heat. We focus on solar PV technology in this Section. As an alternative to solar PV, the sun’s energy can be actively used using concentrating solar power (CSP). Here, the sun’s energy is used to boil water, which is then used to provide power in the form of electricity or heat. This is a relatively minor technology, considered alongside other existing and emerging power generation technologies in Section 3.5. CSP is, perhaps, one of the more interesting of these, however, in that it is linked to recent developments in desalination, discussed separately in Section 3.6. Aside from the active solar technologies, passive solar techniques do not require working electrical or mechanical elements. They include the selection of materials with favourable thermal properties, designing spaces that naturally circulate air, and referencing the position of a building to the sun. Some consideration of this, together with active technologies for distributing renewable sourced heat in buildings, is given in Section 4 of this Report. Alternative Technical and Market SolutionsSystem Configuration: Solar PV systems are highly scalable, ranging from the small rooftop system at the residential premise to large solar PV parks with 50 MW or more capacity. The smaller premise or community-based systems generally range in capacity from 10 kW to 1 MW, and are not usually connected to the grid. The core of the system, the PV cell, is small. PV cells convert solar radiation into direct current electricity. The larger the system, the more PV cells there are, the more complex the way in which they are arranged. In a PV system, PV cells are grouped together in modules. These modules are them connected together in arrays. In larger systems, connected to the grid, arrays can be fixed together to form a number of sub-fields, from which electricity is collected and transported towards the grid connection (see Figure 60). Figure 60: Layout of a Typical Solar PV Park12 
The solar cells are the most expensive element of the PV system, but not the one generally containing copper. The copper comes in the cables connecting the modules (module cable), the arrays (array cable) and the sub-fields (field cable). Whether the system is connected to the grid or not, the electricity collected from the PV cells needs to be converted from DC to AC and stepped up in voltage. This means that inverters are required. These are expensive items, containing copper windings and power electronics. Solar Cells: The falling cost and rising efficiency of solar cells has been key to the commercialisation of solar PV. There are a number of competing technologies for solar cells. Materials presently used for photovoltaics include monocrystalline silicon, polycrystalline silicon, microcrystalline silicon, cadmium telluride, and copper indium selenide/sulfide. They typically convert 15% of incident sunlight into electricity, typically allowing the generation of 100 to 150 kW/hours per square metre of panel per year. The industry recognises three generations of solar cell, of which only the first is fully commercialised. First generation technologies are still in development, and likely to hold their market position against newer alternatives for some time to come. First-generation PV technology (silicon p- n junction or wafer solar cells) is based on single or multi-crystalline silicon (xSi) with an optically thick single semiconductor junction. The practical efficiency limit for this product is around 20% conversion rate. Although reasonably efficient and robust, the technology is expensive. With supply shortages in the latter part of the last decade, costs were as high as US$4/watt peak13, but have fallen and are expected to fall further to US$1.0- 1.5/watt peak.14. The second-generation technology covers low-cost, low-efficiency thin-film cells. The idea is that, while efficiency levels are low (6-12%), the much reduced cost of production will allow the overall cost in relation to the electricity generated to be lower. The target is for costs lower than US$1 per watt peak. The options currently under development include Copper Indium Gallium Selenide (CIGS), Cadmium Telluride (CdTe), Amorphous Silicon (aSi) and Micromorphous Silicon (mSi). Cadmium Telluride (CdTe) is the only one of the thin-film technologies to demonstrate commercial competitiveness agains xSi, with direct manufacturing costs as low as US$1.12 per watt peak. The opportunity for further technical development of this technology is thought to be limited, while a global shortage of telluride mitigates against its use. Amorphous Silicon (aSi) technology has also been commercialised, but only in for low power applications such as calculators. Using a multi-layer construction, the use of aSi is said to be applicable to the electricity generation market. The low cost of aSi could make this attractive, but the multi-layer construction is expensive, a likely barrier to the wide application of this product. Micromorphous Silicon (mSi) technology combines two different types of silicon, microcrystalline and amorphous, in a photovoltaic cell. The solar cells made from these materials tend to have quite low. Amongst the second generation technologies, only Copper Indium Gallium Selenide (CIGS) appears to offer a large commercial potential: This is a low cost technology that, under laboratory conditions, has shown an efficiency rating similar to xSi. Although in practice efficiency is lower, Ascent Solar having claimed to achieve only 11.7% (the highest recorded), costs per watt hour still promise to be very low. Cost per watt hour peak of US$0.50 to 1.0/watt15 is thought to be achievable. While the word “copper” is in the description of CIGS, in fact copper content is quite low, at about 50 kg per MW of capacity16. Figure 61: CIGS Cells 
The third generation solar cell technologies are still at the research phase, but could lead to commercial products by the end of this decade. The aim is to achieve both high efficiency and very low cost. The main methods being explored include dye-sensitised cells, organic (polymer-fullerene) cells, and ETA cells (Extremely Thin Absorber). Cables: As solar generation systems can be spread over a large area with many connections within and between modules and arrays, and then connection between arrays in sub-fields and linkage to the network, the amount of cabling involved can be huge. Typical diameters of the cables used are as follows: module cable 4-6 m2, array cable 6-10 m2 and field cable 30-50 m2. As well as being a large market, the technical requirements of the cable in solar PV systems are high, as the environment is testing. Amongst the characteristics required are temperature resistance, outdoor survival when exposed to ozone and UV light, resistance to rodent or insect attack and long-term operability. For rooftop installation, low smoke and toxin release in the event of a fire are also required. Directory: wordpress -> wp-content -> uploads -> 2017 uploads -> Professor rona s beattie and dr david bamaung glasgow caledonian university email for corresponding author uploads -> Best Offensive Players: qb #19 keenan reynolds, N, ’16. Lg #57 E. K. Binns, N, ’16 uploads -> Smart Supervision Research Partner Orientation Course fy13 and fy14 Grantees September 29- october 1, 2015/San Antonio, tx uploads -> Autonomous Control for a Reliable Internet of Services (across) 2017 -> 6 Thai Market Analysis 2017 -> Birchwood intermediate school 2017 -> Operation corporate 2017 -> This document is written for the amateur radio operator that will be using the PiGate as an emergency communications device in a disaster situation Download 10.26 Mb. Share with your friends:
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