Kalowekamo_ Baker_Outsourcing_book_temp.qxd 01/03/2010 16:51 Page 79
Potential of Purely Organic Solar Cells to Reduce the Cost of Photovoltaics
Table 5: Comparison of Cost Estimates for Purely Organic Solar Cells versus Projected Cost Estimates for Other Thin Films and Multicrystalline Silicon
b
Technology Materials Process Costs Overhead Costs Module Manufacturing Module Cost
a2 2 2
(US$/m ) (US$/m ) Costs (US$/m ) (US$/Wp)
Active (US$/m2) Inactive (US$/m2) Total (%)
Purely organic solar cells 6.7–10.0 16.70–27.48 27–48 9.30–69.60 13.78–25.21 48.80–138.80 1.0–2.83
DSSC(1)* 10.3–16.0 5.22–5.51 22–23% 7.69–10.88 11.6 36.55–46.19 0.75–0.94
DSSC(2)# 23.54 97.59 80 18.07 1.23–10.95 157.66 3.22
CdTe† 6.84 58.86 53% 30.11 27.38 129.33 1.65
mc-Si+ 150.57 57.49 57% 95.81 23.27 343.50 2.34
a Takes into account 95% cell yield; b Representative efficiencies used: 5% for purely organic solar cells (POSCs), dye-sensitised solar cells (DSSCs) (1) and DSSCs (2); 8% for cadmium telluride (CdTe); and 15% for
multicrystalline silicon (mc-Si); 98% module yield for all. *Estimates by Smestad et al., 1994; #Estimates by Meyer, 1996; † Estimates by Zweibel, 1999; +Estimates by Little and Nowlan, 1997.
impact of lifetime on LEC is most important when the lifetime is short;
Figure 4: Electricity Costs in the US
at longer lifetimes it flattens out. Manufacturing cost is much more
16
important when efficiency is low, with a maximum spread of
$0.36/kWh between the high and low estimates of manufacturing
12
cost. This should be compared with a maximum spread of $0.11 when 10
efficiency is high.
8
6
Summary
The manufacturing costs for POSCs are estimated to be between 4
US$48.8 and US$138.9/m
2
, resulting in a module cost between US$1.0
2
and US$2.83/Wp if one considers 5% module efficiency, 98% module
0
yield and 1,000Wp power output per square metre. In this cost
Coal Gas Wind Nuclear Oil POSC
range, POSCs compete economically with TFSC technologies and
LEC low LEC high
traditional silicon-based PV technologies. However, assuming an
efficiency of 5% and a lifetime of five years results in LEC between Production costs of electricity in US based on 2002 averages and that of purely organic solar cells (POSCs)
based on our estimates.
US$0.49 and US$0.85/kWh, a cost that is far from being competitive
in the general electricity market. If the industry can achieve efficiencies
Figure 5: Levelised Energy Cost versus Lifetime
of about 15% and lifetimes of 20 years, LEC is estimated to range from
US$0.07 to US$0.13/kWh. 100
The most important factor in the manufacturing cost of POSCs is the
80
substrate cost. In fact, the major benefit from POSCs appears to be much
lower substrate costs. If these costs could get even lower than the
60
estimates made in this research, it would be a great advantage to POSCs.
If, on the other hand, the cost savings achieved are over-estimated,
40
POSCs may lose some of their competiveness with other TFSCs.
20Levelised energy cost ( cents/kWh)
The cell yield has the potential to derail POSCs if it is not able to be held
at a consistently high value. The single most important factor to the
0
module cost and the LEC is the cell efficiency. At current efficiencies of
5110 5202530
5%, POSCs are is nowhere near competitive with non-solar electricity.
Lifetime (years)
If higher efficiencies can be achieved, POSCs start to look much more
5% efficiency, high 5% efficiency, low
attractive. Finally, the lifetime of the cells appears to present a hurdle –
15% efficiency, low15% efficiency, high
there is great improvement in LEC if cells last 10 or more years.
Levelised electricity costs (LEC) for purely organic solar cells (POSC) as a function of cell lifetime and
Extending the lifetime from 20 to 30 years has much less impact.
efficiency based on the baseline low- and high-end overall module manufacturing cost estimate.
This is a preliminary estimate of POSC costs. It shows that POSCs have
the potential to reduce the cost of PV electricity by four-fold. However, Acknowledgement
much work remains to be done on understanding the particular This study was made possible with financial support from the
processes for producing POSCs and the capital and labour costs Fulbright Scholarship awarded to Joseph Kalowekamo by the US
associated with them. n Department of State.
1 Martin I, Hoffert KC, Jain AK, et al., Nature, 1998;395. 6 Meyer T, Thèse N° 1542, École Polytechnique Fédérale de 9. Zweibel K, Technical Report NREL/TP-520-38350, 2005.
2 Lewis NS, Nocera DG, Proc Nat Acad Sci, 2006;43:15729–35. Lausanne, 1996. 10. Kapur VK, Basol BM, Kissimmee, Florida, 1990.
3 Energy Information Administration, Available at: 7. Haynes KK, Baumann AE, Hill R, Proceedings of the 12th EC 11. Zweibel K, Sol Energy Mater Sol Cells, 2000;63:375–86.
www.eia.doe.gov/emeu/aer/elect.html PV Solar Energy Conference, Amsterdam, The Netherlands, 12. Little RG, Nowlan MJ, Prog Photovoltaic Res App,
4 Kalowekamo J, Baker E, Solar Energy, 2009;83(8):1224–31. 1994. 1997;5:309–15.
5 Smestad G, Sol Energy Mater Sol Cells, 1994;32:259–72. 8. Keshner M, Arya R, NREL Report No. SR-520-36844, 2004.
MODERN ENERGY REVIEW VOLUME 2 ISSUE 1
79
Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86  |  Page 87  |  Page 88  |  Page 89  |  Page 90  |  Page 91  |  Page 92  |  Page 93  |  Page 94  |  Page 95  |  Page 96  |  Page 97  |  Page 98  |  Page 99  |  Page 100  |  Page 101  |  Page 102  |  Page 103  |  Page 104  |  Page 105  |  Page 106  |  Page 107  |  Page 108