Going from Coal to Air Heat Source Pump and PV's using ECO4 grant scheme

Pec123

Financial

Generation

The system is expected to generate 3399 kWh per year

initially, decreasing gradually as the solar cells degrade. Over

the 25 year term of this fnancial projection the total

generation is expected to be 79867 kwh, of which 28654 kWh

will be consumed on site and 51212 kWh exported.

Payback

After adjusting projected costs and benefts for infation, and

applying a discount rate of 4%, the initial system cost of £0.01

is expected to be recouped after 25+ years.

Net Present Value

The total present value of future benefts and costs, using a

discount rate of 4% per year, is £17,216.57. The cost of the PV

system is £0.01. The net present value of the project is

therefore £17,216.56. A positive net present value is a good

indication that the project is fnancially worthwhile.

IRR

The Internal Rate of Return is a useful measure for comparing

the relative proftability of investments.

Disclaimer

Our fnancial model calculates the benefts of a solar PV installation (such as savings in

electricity, or payments for exported electricity) and costs (the initial purchase cost, and

any future maintenance costs if entered), over the projected lifespan of the system.

Values are corrected for infation, system degradation, and discount rate - a measure

that accounts for the fact that a promise of a monetary sum in the distant future is

usually considered less valuable than the promise of the same sum in the near future.

A model is only as accurate as the assumptions it makes. You should consider whether

the values chosen are appropriate for your situation. There are many variables that

dictate the fnancial return of a solar installation and we cannot forecast how they may

change in the future. This fnancial projection shows a likely scenario for future fnancial

returns. Actual returns may vary signifcantly from this forecast.

Assumptions

Infation rate 2%

Cost of electricity £0.5 /kWh

System size 4 kWp

Discount rate 4%

Projection length 25 years

increases with infation

degrades at 0.5% per year

80

MWh

25+

years

£17216.

56

N/A

%

Income and savings

The projected income from the system

over the project lifetime in payments

for generated and exported electricity,

along with electricity savings, are

shown in the table and graph below.

These fgures assume an infation rate

of 2 percent.

Export payments

Electricity savings

Total

Year 1 329 614 944

Year 2 334 623 958

Year 3 339 633 972

Year 4 344 642 986

Year 5 349 652 1001

Year 6 355 661 1016

Year 7 360 671 1031

Year 8 365 681 1047

Year 9 371 691 1062

Year 10 376 702 1078

Year 11 382 712 1094

Year 12 388 723 1110

Year 13 393 734 1127

Year 14 399 745 1144

Year 15 405 756 1161

Year 16 411 767 1178

Year 17 417 778 1196

Year 18 424 790 1213

Year 19 430 802 1232

Year 20 436 814 1250

Year 21 443 826 1268

Year 22 449 838 1287

Year 23 456 851 1307

Year 24 463 863 1326

Year 25 470 876 1346

Total Export Payments £9889 over 25 years

Electricity savings £18444 over 25 years

0

200

400

600

800

1000

1200

1400

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

The bottom line

The table and graph below show the

discounted costs for the project

(including the initial capital required for

the installation), against the total

discounted benefts from income and

savings on electricity bills.

The system does not pay for itself in

the 25 years of this fnancial projection.

Discounted benefts

Cumulative benefts

Discounted costs

Cumulative costs

Cashfow

Year 1 925 925 0 0 925

Year 2 901 1826 0 0 1826

Year 3 878 2704 0 0 2704

Year 4 855 3559 0 0 3559

Year 5 833 4392 0 0 4392

Year 6 812 5204 0 0 5204

Year 7 791 5995 0 0 5995

Year 8 771 6766 0 0 6766

Year 9 751 7517 0 0 7517

Year 10 732 8249 0 0 8249

Year 11 713 8962 0 0 8962

Year 12 695 9656 0 0 9656

Year 13 677 10333 0 0 10333

Year 14 659 10992 0 0 10992

Year 15 642 11634 0 0 11634

Year 16 626 12260 0 0 12260

Year 17 610 12870 0 0 12870

Year 18 594 13464 0 0 13464

Year 19 579 14043 0 0 14043

Year 20 564 14607 0 0 14607

Year 21 549 15156 0 0 15156

Year 22 535 15692 0 0 15692

Year 23 522 16213 0 0 16213

Year 24 508 16721 0 0 16721

Year 25 495 17217 0 0 17217

Pec123

Self consumption

We model here the performance of a solar PV system over the course

of a year, using high resolution minute-by-minute generation data for a

typical PV system and consumption data for a typical house, and

calculating the fow of energy from the solar panels to the house

during the day, and from the grid back to the house at night.

We provide yearly profles of generation, consumption and import /

export, along with detailed profles for a typical spring day.

Consumption

Electricity consumed in the

property each year

3900 kWh Generation

Electricity generated by

the PV array each year

3398 kWh

Self consumption

Proportion of PV

generation used in the

property

36 % Independence

Proportion of electricity

consumption provided by

PV

31 %

Import / Export

Electricity import / export

each year from the

property

Pec123

Performance Summary

A. Installation data

Installed capacity of PV system - kWp (stc) 4 kWp

Orientation of the PV system - degrees from South See individual inputs

Inclination of system - degrees from horizontal See individual inputs

Postcode region 1

B. Performance calculations

kWh/kWp (Kk) See individual inputs

Shade factor (SF) See individual inputs

Estimated output (kWp x Kk x SF) 3399 kWh

Important Note: The performance of solar PV systems is impossible to predict with certainty due to the

variability in the amount of solar radiation (sunlight) from location to location and from year to year. This

estimate is based upon the standard MCS procedure is given as guidence only for the frst year of

generation. It should not be considered as a guarantee of performance.

Shading will be present on your system that will reduce its output to the factor stated. This factor was

calculated using the MCS shading methodology and we believe that this will yield results within 10% of

the actual energy estimate stated for most systems.

Pec123

Not very good with technology so have provided the basic data. Not sure what questions to ask. What stands out for you?

matt_drummer

Your cost is £0.01?

QrizB

matt_drummer said:

Your cost is £0.01?

Pec123 said it was an ECO4 installation, so free of charge to the householder.

matt_drummer

QrizB said:

matt_drummer said:

Your cost is £0.01?

Pec123 said it was an ECO4 installation, so free of charge to the householder.

Just making sure, more of a rhetorical question really

So then, whether you are any good with technology or not, I can't see anything not to like!

I would be more than happy to accept what I was offered.

Qyburn

Pec123 said:

1952 semi detached three bedroom house 116sqm, they will be putting insulation in, coal heating/water with a Rayburn.

What insulation is being installed? A house from that date might be brick cavity walls, plastered on the hard. Is it a suspended timber floor downstairs, or concrete? Window presumably already replaced from original.

Pec123

Qyburn said:

Pec123 said:

1952 semi detached three bedroom house 116sqm, they will be putting insulation in, coal heating/water with a Rayburn.

What insulation is being installed? A house from that date might be brick cavity walls, plastered on the hard. Is it a suspended timber floor downstairs, or concrete? Window presumably already replaced from original.

I'll have to find out insulation. In the eaves. We already have brick foam filled cavity walls. Suspended timber floor downstairs. Windows already replaced with the vented kind,

Pec123

The options we have been given: 

1. *HIB* Longi HiMo5 400W All Black Mono solar panel 10

SolaX X1-3.6T 1ph (inc WiFi dongle) inverter 

2.  Longi 425w white backsheet solar panel 10

Growatt MIN 3600 TL-X Dual MPPT 1ph (inc DC isolator) inverter

Which is more valuable?