Power system expansion planning in Pakistan, in Interim period – i.e. period before open access

Power system expansion planning in Pakistan, in Interim period – i.e. period before open access

Introduction

 Power sector additions in the last five years have been impressive; by 2018 the gap between demand and supply will almost be bridged. This impressive performance has been marred by some missteps, planning has been a weak area and power sector decisions have been taken without needed analysis and due process.

Pakistan’s power sector structure moved from a vertically integrated utility to a single buyer model. Induction of private sector necessitated that the decision making process needed to involve sensibilities and concerns of various players, use of Long term system expansion optimization software was discontinued. NTDC Planning do undertake a master planning exercise that uses optimization software but this is not a document that figures in the decision making process and is in any case updated after every few years and is therefore not current at all points in time. Power sector generation capacity, decision making is in any case fragmented, WAPDA, NTDC, PPIB, AEBD, Provincial Government Energy Departments, AJ&K and GB Power departments, Ministry of Finance, Planning Commission all play a role in this decision making, which is not closely coordinated. Mainly because in the period of shortages any capacity addition was welcome, now that the capacity gap is being bridged , such decisions are coordinated with CPPA/NTDC who verify that the capacity addition is required  as per the demand forecast and other works in progress.

The decision to liberalize the market was taken years ago and along with that decision it was deemed unnecessary to continue the use of WASP and a central power system expansion planning. It was considered that the private sector will take care of such needs. The privatization got stuck and after a partial incomplete transition the effort was stalled, in this period capacity was procured by both the private sector and the public sector routes. Addition of large hydroelectric structures was dealt by WAPDA, in the public sector. This period saw a very weak planning regime and possibly due to that there were gaps in supply and demand and other errors were also made.

 The system is stated to become a mutli-buyer market in the near future, where investment decisions’ will be taken by a multitude of players using different techniques and software. The present arrangement has not entirely worked in so far as capacity additions are concerned .There , however, has been an error made in adding to much capacity , and also by adding too much base load capacity, both actions have financial implications. The interim period ( before open access )  requires that planning error should not be made, it is proposed that:

1.      .GM Planning NTDC Office should be equipped with WASP ( or some other generation expansion optimization tool) . Capacity building would be required to enable professionals to use WASP. WASP should be used as a verification tool. Decisions like how much base load capacity is to be added in each year should be taken by using WASP. 

2.     Base load Capacity: Thar (and other domestic) coal should have priority when base load capacity is required to be added. RLNG based base load should be considered for diversification purposes  Intermediate and peak load capacity should be : hydropower ; biomass including bagasse( but excluding Bagasse with imported coal)

3.     Foreign exchange needs to be shadow priced to present the cost of making capital investments based on foreign currency.

4.     Institutional arrangements: NTDC Office of GM Planning should be entrusted with planning of the power system, the following is recommended: NTDC Power Planning (NTDCPP) be spin off as an independent authority, with the mandate to carry out; least cost expansion planning; transmission system planning; secondary system planning. In the interim period generation expansion planning  should utilize WASP ( NTDC is familiar with WASP although WASP does have some limitations related to modeling hydroelectric power capacity) ; the system is evolving into a multi buyer system , with this transition centralized power system planning will not be desirable , NTDC Power Planning needs to acquire other software which is utilized for modeling  new generation addition to the system in a mutli buyer market , this service ( and other services) should be provided at cost ; NTDCPP is currently under staffed , positions sanctioned should be filled with immediate effect ; for NTDCPP to act as a planning expert there is need to provide more trained staff to man the generation expansion and transmission expansion planning functions ; have been less than proficient in use of software to carry out secondary system planning, There is need to shift the function of secondary transmission planning to .NTDCPP.   

5.      Induction of small hydroelectric , wind, solar power plants has been stalled due to non availability of transmission interconnection to the grid .All of these including biomass based power generation are indigenous resources of energy and are therefore  contributors towards increase in local content in energy utilization. All of these except biomass are seasonal and are not base load plants. There is reluctance in allowing a free field to solar and wind on grounds of: seasonality of supply; and transmission constraints presently a committee in the MoE decides quantum of wind energy to be added each year. With loaming capacity surplus and NEPRA’s decision to only add wind and solar capacity after competitive bidding all these renewable resources will find scant space in new capacity addition. NTDC needs to use WASP to determine quantum of base load capacity tom be added and also to determine the amount of renewable capacity to be added .Decisions related to what capacity is to be added should be made much in advance and should not be sudden and abrupt , hurting investor confidence . Evacuation of power limitations is one reason cited for the reluctance to add renewable to the system, intermittent nature ( except biomass which is base load) is stated to be the other reason, cost considerations have been addressed mainly by the fast reducing cost of wind and solar power plants. GOPA study commissioned by USAID stated that there are very little system constraints against adding about 2224 MWs renewable capacity. Beyond that major reinforcements to the system will be required. The recommendations of the GOPA study (these are presented below) need to be implemented. Wind potential is located in areas which are either far away from the grid system or are located in areas where surplus power is available, therefore there is need to transmit this power to load centers using primary transmission.

6.     Capacity building and enhancement- NTDC Planning needs that the already approved positions are filled with qualified staff with immediate effect. There is also need to enhance the man power  assigned to NTDC Planning  to take up the additional generation expansion and transmission system expansion planning, along with capacity enhancement a proper detailed and  sustained effort is to be made to build capacity in NTDC planning

Gopa Study: GOPA study presents an analysis of the Pakistan Grid with reference to RE interconnection. The conclusions reached are:

1.     2224 MW wind and solar capacity can be added, with the following grid additions: 25 MVAr capacitors at Bhan Saedabad grid station; 120 MVAr Thyristor controlled reactor (TCR) inductive 200 MVAr MSC Capacitive SVC at Lal Suhanra.; Power system stabilizers (PSS) at two synchronous generators at Hub and Jamshoro. ; And operation of some renewable generators in voltage droop control mode would be beneficial.

2.     In the next phase major additional reinforcements are required these would allow the full 4067 (phase I) of renewable generation to be added but it will also facilitate addition totally 9332 MW (including the 4067 MW capacity discussed earlier) of renewable energy to be added. Improvements required are :  Lal Suhanra region requires reinforcement of 220kV system where a new collection substation is to be installed  and two radial 220kV lines are closed to form a ring  This requires addition of 80 km double circuit 220kV transmission lines , 5 km single circuit 220kV transmission line and 5 additional 220/132 kV power transformers including transformer bays . Reinforcements of the Southern wind corridor requires a new 500kV Jhampir grid station , 90 km 220kV and 500kV transmission lines , a 200MVAr capacitor at Jhampir and 100 MVAr shunt capacitors at Gharo are required .  600MVAr SVC (600MVAr TCR and 300MVAr TSC) at Shikarpur are also required.

3.     Spinning reserve requirements will increase to 1500 MW 500MW more than required by the system in 2018, Thus RE will need an additional 500 MW spinning reserves.

4.     Dispatch will, require to: re-execute wind and OV prediction at 1-4 hours ahead; and shorten the dispatch cycle from 30 min to 15 min.

5.     Wind and PV generators need to have provisions for operation in defined conditions. (Modern VRE plants connect to the grid using electronic power converters or inverters; these can be programmed to allow the way in which a VRE power plant behaves on the power grid to be controlled.) 

6.     Addition of specified levels of RE generation results in a higher NPV as compared to the one without RE capacity.

There is consensus on the fact that addition of up to 30% RE capacity is possible with needed inductive loads and SVCs but higher than that capacity will require new approaches on operating and extending grids. Variability of RE due to weather Introduces uncertainty in generation output .These could affect 70% of solar capacity due to cloud cover and 100% of wind capacity due to still days. This requires base load capacity that can follow load to be interconnected, these are costs. To reduce reserves and spinning reserve costs it is recommended that: there needs to be improvement in weather and wind forecast accuracy; forecasts should be for shorter periods than a day

Conclusions

There is need to put in place a set up for power system generation expansion planning  in the interim period. This is necessary because mistakes that were made in the last five years are not repeated in the future. This will need reintroduction of WASP as an optimization tool, and capacity building and enhancement of planning function currently housed in NTDC. There is need to spin off this unit (along with load flow capability) into a separate national organization.